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THK ELECTRIC RAILWAY TEST COMMISSION AND EXECUTIVE COMMITTEE. 



W. E Goldsborough 
Jas. H. McGraw. 
H. H. Norrle. 



W. J. Wil2Ut=. 

J. G, White. 

Geo. F. McCulloch. 



H. T Plumb. 
H. H Vreeland 
B. V. Svvenson. 



EEPORT 



OF THB 



Electric Railway Test Commission 

TO THB 

President of the Louisiana Purchase Exposition 



Members op the Commission : 
J. G. WHITE, Chairman 

GEO. F. Mcculloch h. h. vreeland 

JAMES H. McGRAW W. J. WILGUS 



NEW YORK 

McGEAW PUBLISHING COMPANY 

1906 



G 



51 



LIBRARY of CONGRESS 
Two CoDies Received 

MAV 24 1906 

Copyright Entry 

class/ CL XXc. No, 
' COPY B. 



Report Edited by 
HENRY H. NORRIS, M.E. and BERNARD V. SWENSON, E.E., M.E. 



COPYRrGHTED, 1906, 
BY THE 

McGraw Publishing Company 
New York 




Hon. David R. Francis, 

President, Louisiana Purchase Exposition. 

Dear Sir: The Electric Railway Test Commission has the 
honor to submit herewith an historical and chronological review 
of the work confided to its care. 

The Commission wishes to express its appreciation of the 
hearty co-operation of the Chief of Electricity during all the 
stages of the work, and to heartily commend the efforts which 
have been put forth by its superintendents in successfully over- 
coming the many obstacles which arose during the conduct of 
the tests, and in the editing and arrangement of this Report. 

The Commission also wishes to express its appreciation of the 
assistance rendered by the committees of engineers who helped 
to plan the scope of the work undertaken; of the results accom- 
plished by the test corps, the United States Bureau of Standards, 
and others w^ho aided directly in the tests; of the kindness of 
the manufacturing and other companies who contributed to 
the work by the loan of instruments, machinery, or otherwise; 
and of the financial assistance of those whose contributions 
made the work possible. 

Very respectfully submitted, 

The Electric Railway Test Commission. 



J. G. White, Chairman. 
H. H. Yreeland, Treasurer. 
James H. McGraw, Secretary. 

W. J. WiLGUS. 

Geo. F. McCulloch. 



Ill 



MEMBERS OE THE COMMISSION. 

J. G. White, President, J. G. White & Company, Chairman. 

H. H. Vreeland, President, Metropolitan Railway Company, Treasurer. 

James H. McGraw, President, The McGraw Publishing Co., Secretary. 

W. J. WiLGus, Vice-President, New York Central and Hudson River Railroad. 

Geo. F. McCulloch, President, Indiana Union Traction Co. 

MEMBERS OF THE EXECUTIVE COMMITTEE. 

W. E. GoLDSBOROuGH, Chief of the Department of Electricity, Louisiana Pur- 
chase Exposition, Chairman. 

H. H. NoRRis, Assistant Professor of Electrical Engineering, Cornell Univer- 
sity, Superintendent. 

B. V. SwENSON, Assistant Professor of Electrical Engineering, University of 

Wisconsin, Assistant Superintendent. 
H. T. Plumb, Assistant Professor of Electrical Engineering, Purdue University, 
Assistant Superintendent. 

MEMBERS OF THE ADVISORY COMMITTEE. 

A. H. Armstrong, General Electric Company. 

Clarence Renshaw, Westinghouse Electric and Manufacturing Company. 

W. S. Arnold, Bullock Electric Manufacturing Company 

W. N. Smith, Westinghouse, Church, Kerr & Company, 

MEMBERS OF THE ENGINEERING COMMITTEE ON TEST OF 
CITY AND SUBURBAN EQUIPMENTS. 

M. G. Starrett, Chief Engineer, New York City Railway Co. 

D. F. Carver, Chief Engineer, Public Service Corporation of New Jersey. 

W. S. Twining, Chief Engineer, Philadelphia Rapid Transit Company. 

MEMBERS OF THE ENGINEERING COMMITTEE ON TEST OF 
INTERURBAN EQUIPMENTS. 

A, L. Drum, Assistant General Manager, Indiana Union Traction Co. 

C. J. Jones, Chief Engineer, Elgin, Aurora & Chicago Railway. 

C. A. Alderman, Chief Engineer, Appleyard System, Springfield, Ohio. 

MEMBERS OF THE ENGINEERING COMMITTEE ON TEST OF 
HEAVY TRACTION EQUIPMENTS. 
F. J. Sprague, Consulting Engineer, New York City. 

B. J. Arnold, Consulting Engineer, New York City. 

W. J. WiLGus, Vice-President, New York Central and Hudson River Railroad, 
New York City. 

F. R. Slater, Assistant Engineer to L. B. Still well, New York City. 

MEMBERS OF THE ENGINEERING COMMITTEE ON NEW ELEC- 
TRIC RAILWAY SYSTEMS. 
B. J. Arnold, Consulting Engineer, New York City. 

P. M. Lincoln, Electrical Engineer, with Westinghouse Electric and Manu- 
facturing Company, Pittsburg, Pa. 

W. B. Potter, Electrical Engineer, with General Electric Company, Schenec- 
tady, N.Y. 

iv 



CONTENTS. 



PART I. 

Page 
Introduction 1 

PART II. 

CHAPTER I. " . 
Service Tests of Electric Cars 35 

CHAPTER II. 
Service Tests of a Single-Truck City Car 76 

CHAPTER III. 
Service Tests of a Double-Truck City Car 116 

CHAPTER IV. 
Service Tests of an Interurban Car . » 145 

PART III. 

CHAPTER V. 
Acceleration Tests of a Single-Truck City Car 199 

CHAPTER VI. 
Acceleration Tests of an Interurban Car 227 

PART IV. 

CHAPTER VII. 
Compressor Station Tests of a Storage Air System of Braking 255 

CHAPTER VIII. 

Braking Tests on a Double-Truck City Car Equipped with Air 

Brakes 292 

CHAPTER IX. 
Braking Tests on an Interurban Car Equipped with Air Brakes 324 

CHAPTER X. 

Braking Tests on a Single-Truck City Car Equipped with Mag- 
netic Brakes 338 

V 



vi CONTENTS 

PART V. 

CHAPTER XI. 

Page 

Tests of a Storage Battery Industrial Locomotive 369 

PART VI. 

CHAPTER XII. 

Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections 389 

CHAPTER XIII. 
Alternating Current Losses in Track 432 

PART VII. 

CHAPTER XIV. 

Train Resistance Tests of Interurban Cars 463 

CHAPTER XV. 
The Test Car " Louisiana " 488 

CHAPTER XVI. 
Air Resistance Tests . 534. 

APPENDIX A. 
General Data Relating to Electric Cars 577 

APPENDIX B. 
Acknowledgments 593 



TESTS. 



Test 

1. Service Tests on a Single-Truck City Car. 

Hand Brake. 

2. Service Tests on a Single-Truck City Car. 

Magnetic Brake. 

3. Service Tests on a Single-Truck City Car. 

Magnetic Brake. 

4. Service Tests on a Single-Truck City Car. 

Hand Brake. 

5. Service Tests on a Single-Truck City Car. 

Magnetic Brake. 

6. Service Tests on a Double-Truck City Car. 

Independent Motor Compressor. Wet Track. 

7. Service Tests on a Double-Truck City Car. 

Independent Motor Compressor. Dry Track. 

8. Service Tests on a Double-Truck City Car. 

Storage Air System. Dry Track. 

9. Service Tests on an Interurban Car. 

Run from Muncie City Limits to Indianapolis: Indianapolis to Ander- 
son. Dry Track. No Trailer. 

10. Service Tests on an Interurban Car. 

Run from Anderson to Muncie : Muncie to Indianapolis : Indianapolis 
to Anderson. Dry Track. No Trailer. 

11. Service Tests on an Interurban Car. 

Run from Muncie to Indianapolis and return to Muncie. Dry Track. 
One Trailer. 

12. Service Tests on an Interurban Car. 

Run from Muncie to Indianapolis and return to Muncie. Dry Track. 
No Trailer. 

13. Acceleration Tests on a Single-Truck City Car. 

Controller Turned to Full Parallel in 40 feet. 

14. Acceleration Tests on a Single-Truck City Car. 

Controller Turned to Full Parallel in 70 feet. 

15. Acceleration Tests on a Single-Truck City Car. 

Controller Turned to Full Parallel in 100 feet. 

16. Acceleration Tests on a Single-Truck City Car. 

Controller Turned to Full Parallel in 150 feet. 

17. Acceleration Tests on a Single-Truck City Car. 

Controller Turned to Full Parallel in 200 feet, 

vU 



viii TESTS 

Test 

18. Acceleration Tests on an Interurban Car. 

Controller to Series Position at once. Car at Rest. Final Contact in 
9.1 Seconds. 

19. Acceleration Tests on an Interurban Car. 

Controller to Parallel Position at once. Car at Rest. Final Contact 
in 20.26 Seconds. 

20. Compressor Station Tests of a Storage Air System of Braking. 

Length of Test, 24 hours. 

21. Compressor Station Tests of a Storage Air System of Braking. 

Length of Test, 2 hours, 35 minutes. 

22. Braking Tests on Double-Truck City Cars Equipped with Air 

Brakes. 
Storage System, 51 Cars. 

23. Braking Tests on a Double-Truck City Car Equipped with Air 

Brakes. 
Storage System. 

24. Braking Tests on a Double-Truck City Car Equipped with Air 

Brakes. 
Motor. Compressor System. Wet Track. 

25. Braking Tests on a Double-Truck City Car Equipped with Air 

Brakes. 
Motor. Compressor System. Dry Track. 

26. Stand Tests of Motor-Compressor. 

Against Constant Pressure, 93 lbs. 

27. Stand Tests of Motor-Compressor. 

Against Pressure from 43.5 to 50.8 poimds. 

28. Stand Tests of Motor-Compressor. 

Against Pressure from 43.5 to 60.6 pounds. 

29. Braking Tests on an Interurban Car Equipped with Air Brakes. 

Air Pressure, 20 pounds to square inch. 

30. Braking Tests on an Interurban Car Equipped with Air Brakes. 

Air Pressure, 20 pounds to square inch, 

31. Braking Tests on an Interurban Car Equipped with Air Brakes. 

Air Pressure, 30 pounds to square inch. 

32. Braking Tests on an Interurban Car Equipped with Air Brakes. 

Air Pressure, 40 pounds to square inch. 

33. Braking Tests on an Interurban Car Equipped with Air Brakes. 

Air Pressure, 40 pounds to square inch. 

34. Braking Tests on a Single-Truck City Car Equipped with Magnetic 

Brakes. 

35. Tests of a Storage-Battery Industrial Locomotive. 

Pulling Against Fixed Anchor. 

36. Tests of a Storage-Battery Industrial Locomotive. 

Running Without Trailers. 

37. Tests of a Storage-Battery Industrial Locomotive. 

Lpcomotive Hauling Trailers, 



TESTS ix 

Test 

38. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Section of A.S.C.E. Standard T-RaU, 26.07 feet long, 56 pounds per yard. 

39. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Section of A.S.C.E. Standard T-Rail, 27.83 feet long, 80 pounds per yard. 

40. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Square Steel Section, 8.56 feet long, 64.15 pounds per yard. 

41. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Round Section, 3 inches in diameter, 8.16 feet long, 72 pounds per 
yard. 

42. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Round Steel Section, 2.5 inches in diameter, 7.63 feet long, 50.6 pounds 
per yard. 

43. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Tool Steel, Square Section, diameter 2.02 inches, 6.95 feet long, 41.3 
pounds per yard. 

44. Alternating Current Losses in Steel Rails and in Other Steel 

AND Iron Sections. 
Wrought Iron Gas Pipe, inside diameter, 3.01 inches, outside diameter, 
3.51 inches, 18.43 feet long, 22.72 pounds per yard. 

45. Alternating Current Losses in Track. 

Direct Current Resistance. 

46. Alternating Current Losses in Track. 

Double Track and Double Trolley. 

47. Alternating Current Losses in Track. 

Double Track Alone. 

48. Alternating Current Losses in Track. 

Single Track and Single Trolley. 

49. Alternating Current Losses in Track. 

Single Track Alone. 

50. Alternating Current Losses in Track. 

Single Rail and Single Trolley. 

51. Alternating Current Losses in Track. 

Single Rail Alone. 

52. Train Resistance Tests of Interurban Cars. 

Resistance Tests with Car No. 284, between Carmel and Noblesville, Ind. 

53. Train Resistance Tests op Interurban Cars. 

Resistance Data Selected from Service Tests of Chapter IV. 

54. Train Resistance Tests of Interurban Cars. 

Resistance Runs with Car "Louisiana" with Parabolic-Wedge Shaped. 
Movable Vestibule, Standard Fixed Vestibule in Position. 



X TESTS 

Test 

55. Train Resistance Tests of Interurban Cars. 

Resistance Runs with Car "Louisiana" with Parabolic Shaped Movable 
Vestibule, Standard Fixed Vestibule in Position. 

56. Train Resistance Tests of Interurban Cars. 

Resistance Runs with Car "Louisiana" with Flat Movable Vestibule, 
Standard Fixed Vestibule in Position. 

57. Train Resistance Tests of Interurban Cars. 

Resistance Runs with Car "Louisiana," Standard Movable Vestibule 
in Position. No Rear Vestibule. 

58. Air Resistance Tests. 

Car "Louisiana" with Parabolic-Wedge Vestibule. 

59. Air Resistance Tests. 

Car "Louisiana" with Parabola Vestibule. 

60. Air Resistance Tests. 

Car "Louisiana" with Flat Vestibule. 

61. Air Resistance Tests. 

Car "Louisiana" with Standard Vestibule. 



TABLES. 



Table Page 

I. Synopsis of Results of Service Tests on Single-Truck City Car, 77 

II. Air and Motor Temperature in Single-Truck Car, Test No. 1, 111 

III. Air and Motor Temperature in Single-Truck Car, Test No. 2, 112 

IV. Air and Motor Temperature in Single-Truck Car, Test No. 3, 113 
V. Air and Motor Temperature in Single-Truck Car, Test No. 4, 114 

VI. Air and Motor Temperature in Single-Truck Car, Test No. 5, 115 

VII. Synopsis of Results, Tests 6-8 116 

VIII. Results of Test No. 6 134 

IX. Results of Test No. 7 136 

X Results of Test No. 8 138 

XI. Synopsis of Results, Tests 9-12 145 

XII. Running Schedule Muncie-Indianapolis Division 154 

XIII. Air Temperature and Wind Data 155 

XIV. Intermediate Results of Test No. 9 168 

XV. Intermediate Results of Test No. 9 168 

XVI. Intermediate Results of Test No. 9, Summary of Tables XIV 

and XV 168 

XVII. Intermediate Results of Test No. 10 169 

XVIII. Intermediate Results of Test No. 10 169 

XIX. Intermediate Results of Test No. 10, Summary of Tables 

XVII and XVIII 169 

XX. Intermediate Results of Test No. 11 170 

XXI. Intermediate Results of Test No. 11 170 

XXII. Intermediate Results of Test No. 11, Summary of Tables XX 

and XXI 170 

XXIII. Intermediate Results of Test No. 12 171 

XXIV. Intermediate Results of Test No. 12 171 

XXV. Intermediate Results of Test No. 12, Summary of Tables 

XXIII and XXIV 171 

XXVI. Result of Test No. 9 177 

XXVII. Result of Test No. 10 180 

XXVIII. Result of Test No. 11 182 

XXIX. Result of Test No. 12 184 

XXX. Synopsis of Results, Acceleration 199 

XXXI. Synopsis of Results, Tests 18 and 19 228 

XXXII. Synopsis of Results, Tests 20 and 21 256 

XXXIII. Average Air Temperatures by Three-hour Periods .... 280 

XXXIV. Average Temperatures of Cooling Water by Three-hour 

Periods 280 

xi 



xu 



TABLES 



Table Page 

XXXV. General Summary by Three-hour Periods . . c . . . . 281 

XXXVI. General Results of Twenty-four-hour Run ....... 281 

XXXVII. Showing Average Temperatures for Test No. 21 Com- 
pared with those for a Similar Period in Test No. 20 . . 282 
XXXVIII, General Summary of 2.35-Hour Run with City Water, 

Arranged for Comparison with Twenty-four-hour Run, 283 
XXXIX. General Comparison to Show Relative Merits of the 

two Systems of Cooling the Air During Compression . 283 

XL. Synopsis of Results, Tests 22-25 293 

XLI. Synopsis of Results, Tests 26-28 294 

XLII. Test No. 22, General Summary of Results 298 

XLIII. Results of Test No. 22, Compression Data 299 

XLIV. Results of Test No. 22, Stop Data 300 

XLV. Air Taken by Cars 300 

XL VI. Test No. 23, General Summary of Results 303 

XL VII. Air Consumption of Car 2600 304 

XL VIII. Tests Nos. 24 and 25, General Summary of Results . . .312 

XLIX. Air Consumption of Car 2600 313 

L. Air Consumption of Car 2600 313 

LI. Tests Nos. 26, 27, and 28, General Summary of Results . 318 
LII. Synopsis of Results, Tests Nos. 29, 30, 31, 32, 33 . . . . 324 

LIII. Synopsis of Results 338 

LIV. Braking Tests of Single Truck City Car Time, Speed and 

Distance Data 352 

LV. Braking Tests of Single-Truck City Car Electrical Data . . 353 
LVI. Synopsis of Results, Industrial Locomotive Tests .... 369 

LVII. Test No. 38 402 

LVIII. Test No. 39 408 

LIX. A. C. Losses in Square Section 416 

LX. A. C. Losses in Round Section 418 

LXI. A. C. Losses in Round Section 420 

LXII. A. C. Losses in Square Section 422 

LXIII. A. C. Losses in Pipe Section 424 

LXIV. Direct Current Resistance of Track „ 446 

LXV. Synopsis of Results of Train Resistance Tests 464 

LXVI. Test No. 52, Resistance Runs with Car "284" (on Test 

Track) .477 

LXVII. Test No. 53, Resistance Runs with Car "284" 478 

LXVIII. Test No. 54, Parabolic-Wedge Front Vestibule, Standard 

Rear Vestibule 481 

LXIX. Test No. 55, Parabolic Front Vestibule, Standard Rear 

Vestibule 482 

LXX. Test No. 56, Flat Front Vestibule, Standard Rear Ves- 
tibule 483 

LXXI. Test No. 57, Standard Front Vestibule, No Rear Vesti- 
bule ...,. . 484 



TABLES 



xui 



Table Page 

LXXII. Table of Grades between Siding 105 and Siding 109 . . 495 

LXXIII. Synopsis of Results of Air Resistance Tests 534 

LXXIV. Data Showing Direction and Velocity of Wind .... 535 

LXXV. Schedule of Runs for Preliminary Tests 537 

LXXVI. Schedule of Runs with Parabolic-Wedge Vestibule . . 538 

LXXVII. Schedule of Runs, with Parabolic Vestibule 542 

LXXVIII. Schedule of Runs with Flat Vestibule 543 

LXXIX. Schedule of Runs with Standard Vestibule 545 

LXXX. Test No. 58, Air Pressure on Car "Louisiana" on Test 

Track 558 

LXXXI. Test No. 59, Air Pressure Tests on Car "Louisiana" on 

Test Track 559 

LXXXII. Test No. 60, Air Pressure on Car "Louisiana" on Test 

Track 560 

LXXXIII. Test No. 61, Air Pressure Tests on Car "Louisiana" on 

Test Track 561 

LXXXIV. Car Body Resistance Data .562 

LXXXV. Power Absorbed by Vestibules 563 

LXXXVI. General Results of Air Resistance Tests 569 

LXXXVII. Power Absorbed by Vestibules, Expressed in Horse 

Power 569 

LXXXVIII. Power Absorbed by Front and Rear Vestibules in 

Kilowatts 570 

LXXXIX. Relative Power Required to Force Front Vestibules 

only, through the Air, at Various Speeds 570 

XC. Power Absorbed by Parobolic- Wedge Front Vestibule 
and Parabolic Rear Vestibule in Overcoming Air 
Resistance, as Compared with that Absorbed by 

Standard Front and Rear Vestibules 571 

XCI. Power Absorbed by Front and Rear Vestibules and 

Car Body, Kilowatts 571 

XCII. Total Estimated Power Absorbed in Overcoming Air 
Resistance by an Interurban Car Equipped with 

Various Vestibules 572 

XCIII. Classification of Electric Cars 578 

XCIV. Data for Light City Service (Single Truck) ..... 582 
XCV. Data for Heavy City Service (Double Truck) .... 582 
XCVI. Data for Heavy City Service, Continued. (Double 

Truck) 584 

XCVII. Data for Light Interurban Service (Double Truck) . . 585 
XCVIII. Data for Heavy Interurban Service (Double Truck, 4 

Motors) 586 

XCIX. Average Data for Light City Service 587 

C. Average Data for Heavy City Service 588 

CI. Average Data for Light Interurban Service 588 

CII. Average Data for Heavy Interurban Service 589 



PART I. 
INTRODUCTION. 



INTRODUCTION. 



The Electric Railway Test Commission. 

The organization of the Electric Railway Test Commission 
was due to the recognition, by the officials of the Louisiana 
Purchase Exposition, of the fact that the presence of a large 
amount of electric railway apparatus, gathered together for 
exhibit purposes, offered an exceptional opportimity for obtain- 
ing practical and scientific information of equal interest to the 
producer and to the user of electrical machinery; and of the 
further fact that such investigations could most advantageously 
be carried out under the auspices of the Exposition. 

In order to take advantage of this opportunity. President 
David R. Francis, in November, 1903, in consultation with 
Professor W. E. Goldsborough, Chief of the Department of 
Electricity, appointed five commissioners to study the situation 
and to devise ways and means for accomplishing the desired 
ends. This commission was selected so as to give representation 
to all branches of the electric railway industry and was made 
up of the following : 

J. G. White, President J. G. White & Company, Chairman. 

H. H. Vreeland, President Metropolitan Railway Com- 
pany, Treasurer. 

James H. McGraw, President The McGraw Publishing 
Company, Secretary. 

W. J. Wilgus, Vice-President New York Central Rail- 
road. 

Geo. F. McCulloch, President Indiana Union Traction 
Company. 



ELECTRIC RAILWAY TEST COMMISSION 



Memorandum by Professor Goldsborough. 

At a meeting of the Commission held on December 17, 1903, 
Professor Goldsborough presented the following draft of sug- 
gested plans for tests which might be satisfactorily taken up by 
the Commission. 

MEMORANDUM FOR THE ELECTRIC RAILWAY TEST COMMIS- 
SION, UNIVERSAL EXPOSITION, ST. LOUIS, 1904. 

I HAVE the honor to present, for the consideration of the Commission, 
a statement of the provision which has thus far been made for the test 
of electric railway apparatus at the Louisiana Purchase Exposition, and 
I have taken the liberty to suggest certain topics which, I hope, will be 
found worthy of consideration by the Commission. 

It is the desire of the Exposition Management that, if possible, ade- 
quate arrangements be perfected for the conduct at the Exposition of a 
most comprehensive series of tests upon electric railway equipment, in 
order that, thereby, a large amount of important scientific and engineer- 
ing information may be compiled for the benefit and use of designers 
and engineers in meeting the great engineering problems now arising, 
which involve enormous expenditures and deal almost exclusively with 
the problem of electric railway construction. 

The Exposition Company has found it possible to provide adequate 
space in the Electricity Building for the installation of all systems which 
will show modern methods for the operation and control of electric cars 
and trains. Exhibitors of such sets will be requested to so arrange their 
installations as to make them available for test in position in the build- 
ing. 

On the grounds the Exposition Company has provided special tracks 
having an almost level grade and well ballasted, for the operation and 
test of such complete electric railway car and locomotive equipments as 
shall be offered. These special tracks consist of one section, fourteen 
hundred feet in length, and a second section, two thousand feet in length, 
the two sections being parallel. I*n addition, terminal facilities have been 
arranged in a prominent location, capable of holding from twenty to 
twenty-five fully equipped cars. 

The site of the special tracks is parallel with the Transportation and 
Varied Industries buildings, and between these buildings and -Lindell 
Boulevard, which is the southern boundary of the Pike. The terminal 
tracks lie between the Varied Industries and Transportation buildings, 



INTRODUCTION 3 

and at right angles to the test tracks. It is beheved that these outdoor 
tracks will afford ample space for very comprehensive tests upon all 
present types of electrically equipped cars and locomotives, including 
the following classes: 

Equipments Operated from a Central Station. 

(a) Cars equipped for city service. 

(b) Cars equipped for interurban service. 

(c) Industrial electric locomotives. 

(d) Mining locomotives. 

(e) Locomotives for steam railway service conditions. 

Equipments Operated by Stored Power. 

(a) Cars equipped for city service. 

(6) Industrial locomotives. 

(c) Mining locomotives. 

(d) Locomotives for steam railway service conditions. 

(e) Heavy tram service, electric automobiles. 
(/) Heavy electric trucks. 

The character to be given the tests made upon the various electrical 
equipments submitted may, it is thought, be divided as follows : 

Tests on Apparatus in Electricity Building. 

(a) Tests on electric railway motor equipments under constant load 
to determine rate of heating during continuous operation. 

(b) Tests on electric railway motor equipments to determine 
efficiency of such motors under different fixed conditions of operation. 

(c) Tests on electric railway motor equipment for the purpose of 
determining their torque curves and accelerating power. 

(d) Tests of hand, automatic, and multiple control systems to 
determine, by repeated tests, the relative economy, certainty, and 
regularity of starting motor car equipments under fixed loads. 

Tests of Electrical Railway Equipments on Experimental Track. 

(a) Acceleration tests on single cars and multiple equipped trains. 

(b) Braking tests on single cars and multiple equipped trains. 

(c) Coasting tests on single cars and multiple equipped trains. 

(d) Motor heating tests on single cars and multiple equipped trains. 

(e) Acceleration tests on locomotives and locomotive trains. 
(/) Braking tests on locomotives and locomotive trains. 

(g) Coasting tests on locomotives and locomotive trains. 

(h) Motor heating tests on locomotives and locomotive trains. 

(i) Tests to determine car and train friction. 



4 ELECTRIC RAILWAY TEST COMMISSION 

The great value of accumulating comprehensive information covering 
all types of standard railway apparatus at this time cannot be over- 
estimated, and eminent authorities can be cited to show that the infor- 
mation at present in the hands of electrical engineers is, to a great ex- 
tent, incomplete and unequal to the present demands of our profession. 

That the test tracks are adequate for the tests outlined above is 
assured when it is remembered that, for a given temperature rise, the 
capacity in tons per motor is practically a fixed amount and indepen- 
dent of the number of stops per mile. The number of stops made by an 
electric car will vary from a maximum of fifteen stops per mile in city 
practice to a minimum of about one stop in five miles in local interurban 
practice. Five stops per mile is a very frequent figure even in inter- 
urban work, whereas the test track facihties admit of a rate of operat- 
ing equivalent to five stops in two miles. 

The tests for determining the heating of electric railway motors in 
service under different conditions of gearing and schedule can be made 
by operating the -car continually over a given length of track as a shuttle- 
train first in one direction and then in the reverse direction. In this 
way conditions can be kept perfectly uniform and wind resistance to a 
great extent eliminated. The effect of passengers can be obtained by a 
dead-weight load upon the car, and variation in the behavior of the car 
under light and heavy loading investigated. 

The importance of these tests will be better appreciated when it is 
remembered that only by an elaborate series of temperature runs made 
upon an exj^erimental track can the degrees rise per watt lost in differ- 
ent parts of a motor be accurately determined. Service capacity curves 
for different conditions of service are, therefore, not absolutely correct 
unless the thermal capacity curves be obtained from actual tests giving 
the same train cycle as that over which the equipment is designed to be 
operated. 

These tests are of special importance in relation to the light which" 
they will throw upon the problem of determining the standard factory 
tests to be applied in the rating of electric railway motors. The rela- 
tion between the commercial one-hour rating of a railway motor and its 
service capacity performance is very difficult to express. In fact it is 
almost impossible to compare two motors differing essentially in their 
mechanical design under present conditions, as the stand test of a motor 
has no direct bearing on its service performance with its different dis- 
tribution of losses and better facilities for ventilation. 

By carrying on a series of exhaustive tests on many individual motor 
equipments, it becomes possible to generalize with a fair degree of ac- 
curacy, and to evolve curves of real value to operating engineers. 

The matter of the imj^ortance of wind resistance tests should not be 



INTRODUCTION 6 

overlooked. Data now at hand have been developed largely through 
tests made upon steam railroads. No conclusive data are at hand re- 
garding the effect of differently shaped car-ends on single or multiple 
car operation. When such data become available, it will be possible to 
much more accurately adapt railway car and train equipments to eco- 
nomic service on the roads for which they are designed. 

If the general matter of tests on electric railway equipments has an 
importance sufficient to warrant such action, it may prove advisable 
for the Commission to enlist the co-operation of the American Street 
Railway Association and the American Railway Mechanical and Elec- 
trical Association, and the appointment by these associations of suitable 
expert committees to investigate and report upon a definite schedule of 
tests for all the electric railway equipments that may be submitted. 
To such committee or committees of experts, the matter of the intro- 
duction of alternating-current power in the operation of electric rail- 
ways can, with advantage, be commended for special consideration, in 
order that this important and now developing branch of electric railway 
service shall not be overlooked, and an early opportunity of securing 
important information relative thereto be permitted to pass. 

In carrying out these tests, the Exposition Company, and particularly 
the Department of Electricity, will provide every facility possible. In 
regard to the matter of appliances for the standardization of instru- 
ments used in connection with the tests, I desire to make the announce- 
ment that the National Bureau of Standards will erect in the Palace of 
Electricity a laboratory fully equipped with every modern apphance 
needed for the most accurate and scientific standardization of all types 
and classes of electrical instruments. 

The importance of this work would seem to warrant the inference 
that important operating and manufacturing companies engaged in 
electrical railroading will find it worth while to co-operate to the extent 
of defraying expenses thereof not otherAvise provided for. 

Respectfully submitted, 

W. E. GOLDSBOROUGH. 



Co-operation with the American Street Railway 

Association. 

At the second meeting of the Commission, held January 27, 
1904, a committee was appointed to draft a communication to 
the American Street Railway Association. The following letter 



6 ELECTRIC RAILWAY TEST COMMISSION 

was prepared in order to acquaint the Association with the pur- 
poses of the Commission and to obtain its co-operation. This 
letter was accompanied by an abstract of Professor Golds- 
borough's memorandum. 

New York, February 1, 1904. 
Executive Committee, 

American Street Railway Association. 

Gentlemen : — By unanimous vote of the Electric Railway Test 
Commission of the Universal Exposition, St. Louis, 1904, I have been 
requested to submit to you the enclosed memorandum which details in 
brief the series of tests which the Commission hope will be successfully 
carried out on electric railway appliances and equipments. 

That this work may be made as valuable as possible to electric rail- 
way interests the Commission invites the co-operation of the American 
StreeURailwaj'^ Association in carrying the work to a successful conclusion. 

It has been suggested that the membership of the American Street 
Railway Association may profitably see fit to delegate certain engineers 
to be in attendance upon the tests and to co-operate in the making of 
records and supervising of experimental details. It is proposed that 
the tests shall be inaugurated on or about the first of July, 1904, to con- 
tinue during the remainder of the Exposition term. 

The way seems open to make the work now in hand of permanent 

and far-reaching value in its effect upon economic operation of electric 

railway properties. 

Very respectfully, 

J. G. White, Chairman. 

James H. McGraw, Secretary. 

The matter was presented to the Executive Committee of 
the Association on February 29, by Mr. Vreeland, who reported 
that his suggestions were heartily received. The following quo- 
tation from the minutes of the Executive Committee indicates 
the cordial feeling which has existed between the Association 
and the Commission. 

The following communication in relation to tests of street railway 
equipment and appliances, and other electrical apparatus, to be made 
during the World's Fair at St. Louis, was read. 

(Then follows Professor Goldsborough's memorandum as on page 2.) 

Mr. Vreeland then outlined the work which it is proposed to perform 

in St. Louis in connection with the tests in question, and suggested that 



INTRODUCTION 7 

the members of the Association should appoint engineers to co-operate 
with those in charge of the tests so as to secure results which will be 
valuable both from a theoretical and a practical standpoint. 

Mr. Hutchins moved that the President and Secretary be authorized 
to communicate with the members of the Association urging them to 
co-operate as far as practicable in the tests above referred to; it being 
the desire of the Executive Committee that one or more engineers rep- 
resenting members of the Association should be present during the tests 
to lend such assistance as may be possible; that the attendance of the 
engineers be arranged for, so that two of them will be present at all 
times, arrangements being made in advance to this effect, it being the 
desire of the Executive Committee that the members shall co-operate 
in this matter to the fullest possible extent. 

Motion carried. 



Announcement of Plans of the Commission. 

The following outline of the plans of the Commission was 
prepared and printed in circular form for distribution among the 
individuals and companies interested in electric railway work. 

outline of the flans of the electric railway test com- 
mission, UNIVERSAL exposition, ST. LOUIS, 1904. 

One of the most important features of the Louisiana Purchase Expo- 
sition to railway men, and certainly one of great permanent value, will 
be the results secured by the Electric Railway Test -Commission. 

The street railway industry of the United States comprises over one 
thousand companies owning and operating over 26,000 miles of single 
track, upon which are transported over five billion passengers per year 
by the use of over 71,000 cars. The aggregate mileage-run by cars 
exceeds one billion miles. More than one and one-quarter million horse 
power are involved, and in money nearly three billion dollars. 

The authorities of the World's Fair, realizing the importance of this 
industry to our civilization and future development, have provided for 
the bringing together of all the types of machinery and appliances that 
enter into the construction and equipment of electric railroads, and, in 
addition to this, have offered facilities for the testing of this class of 
apparatus that have never before been available for such a purpose in 
the history of the development of electric traction. 

The authorities of the Exposition thereupon appointed an Electric 
Railway Test Commission for the purpose of making elaborate and 



8 ELECTRIC RAILWAY TEST COMMISSION 

accurate tests on electric railway apparatus, and to take every advan- 
tage of the facilities thus placed at their disposal. It is the intention of 
the Commission to test not only the electric railway equipments of 
standard types, but systems and apparatus now being developed, and to 
have demonstrated the utility of electric railway signal apparatus and 
safety devices of every form. 

The exhibits in the Palace of Electricity will comprise principally 
motors, controllers, switchboard and auxiliary apparatus. Outside of 
this building, there are two parallel tracks 1,400 feet in length, and two 
parallel tracks 2,000 feet in length, upon which speed, acceleration, 
braking, and efficiency tests can be conducted. All the electric railway 
features, even if located in or about the Transportation Building, are 
to be, as is eminently proper, under the direction of the electrical depart- 
ment, and not under the steam railroad department of transportation 
as has been the case in previous expositions. 

Through the liberality of the Indiana Union Traction Company, the 
Commission has obtained unusual opportunities for making high speed 
and heavy traction tests. The track placed at their disposal by the 
Indiana Company is eight miles in length, well ballasted, straight, and 
practically level throughout its entire length. 

The Executive Committee of the American Street Railway Associ- 
ation, at a meeting held in New York on February 29, 1904, promised 
the Commission their hearty co-operation in the execution of their work. 
The interest and co-operation of the leading manufacturers of electric 
railway apparatus have also been secured. As an illustration of this, 
three new single-phase, alternating-current motors have been offered the 
Commission for testing purposes. Special tests will be arranged for 
them, on account of alternating-current railway apparatus being one of 
the newest developments in railway engineering practice, and therefore 
of unusual interest. 

In order that the plans of the Commission might be executed under 
the most favorable conditions, the work has been divided into four 
main branches, and special committees of engineers, who are specialists 
in the several branches of electric railway work, have prepared schedules 
of the tests which will be made of the equipment offered in each class. 
These special committees on the scope of the tests are: 

Engineering Committee on Test of City and Suburban Equipments. 

M. G. Starrett, Chief Engineer, New York City Railway Company. 
D. F. Carver, Chief Engineer, Public Service Corporation of New 

Jersey. 
W. S. Twining, Chief Engineer, Philadelphia Rapid Transit Company, 




THE ADVISORY AXD ENGINEERIXG COMMITTEES. 



A. II Arinstiong. 
D. F. Carver. 

B. J. Arnold, 
t-'harles Jonei«. 
Clarence Ren s haw. 



>I. G. Starrett. 
P M. Lincoln. 
Fraik J. Spn=gue. 
A. L. Drum. 
W. S. Twining. 



W. S. Arnold. 
('. A. Alderman. 
W. B. Potter. 
F. R Slater. 
W. N. Smith. 



INTRODUCTION 9 

Engineering Committee on Test of Interurhan Equipments. 

A. L. Drum, Assistant General Manager, Indiana Union Traction 
Company. 

Charles Jones, Chief Engineer, Elgin, Aurora & Chicago Railway. 
C. A. Alderman, Chief Engineer, Appleyard System, Springfield, Ohio. 

Engineering Committee on Test of Heavy Traction Equipments. 

F. J. Sprague, Consulting Engineer, New York City. 

B. J. Arnold, Consulting Engineer, New York City. 

W. J. Wilgus, Vice-president, New York Central & Hudson River 

Railroad, New York City. 
F. R. Slater, Assistant Engineer to L. B. Stillwell, New York City. 

Engineering Committeeon New Electric Railway Systems. 

B. J. Arnold, Consulting Engineer, New York City. 

Paul M. Lincoln, Electrical Engineer wdth Westinghouse Electric & 
Manufacturing Company, Pittsburg, Pa. 

W. B. Potter, Electrical Engineer with General Electric Company, 
Schenectady, N. Y. 

The information available at the present time for those interested 
in the construction and operation of electric railways is the result of 
numerous laboratory and shop tests that have been made both by manu- 
facturing and operating companies, and, while these data are of value 
within the limits of precision of measurement, the tests do not afford 
a proper basis of comparison as between apparatus and equipments 
from various manufacturers, owing to the widely differing conditions 
under which the tests have been made. 

It is therefore the belief of engineers and railway operators that the 
results of a properly conducted series of tests, under absolutely uniform 
conditions, will be invaluable. These results will be systematically 
arranged and published in book form, and the volume will undoubtedly 
be a valuable contribution, not only to the electric railway profession, 
but to engineering literature as well. 

Electric Railway Test Commission. 

J. G. White, Chairman. 
H. H. Vreeland. 
W. J. Wilgus. 
James H. McGraw. 
George F. McCulloch. 
Cpmmission Headauarters, 43-49 Exchange Place, New York. 



10 ELECTRIC RAILWAY TEST COMMISSION 



Reports of the Engineering Committees 

The four engineering committees submitted reports, which, 
taken collectively, form an outline of the present status of the 
electric railway and also indicate the various directions in which 
the art is progressing. 

eeport of committee on test of city and suburban 

electric railway equipments. 

March 9, 1904. 
Electric Railway Test Commission, 

Mr. J. G. White, Chairman, 

Nos. 43-49 Exchange, New York. 

Gentlemen: Your Engineering Committee on Tests of City and 
Suburban Equipment, realizing that the field of research assigned to 
it is somewhat limited and has been covered time and again by engineers, 
manufacturers of equipments, and users of equipments, nevertheless 
believes that such tests as have been made do not afford a proper basis 
of comparison as between motor equipments from different manufac- 
turers, owing to the widely differing conditions under which such tests 
have been made. 

We believe that the results of a proper series of tests conducted under 
the authority of your Commission and under absolutely uniform con- 
ditions will be of great value to engineers and users of motor equipments 
generally, as furnishing a reliable basis of comparison between the equip- 
ments tested. 

We, therefore, wish to recommend in a general way that all tests 
undertaken be made as complete as possible, and that particular atten- 
tion be given to details to the end that the greatest possible uniformity 
of conditions may be obtained, insuring the absolute reliability of results 
of the tests. 

Specifically we would recommend that as far as possible tests be con- 
ducted along the following lines: 

Tests on Apparatus in Electricity Building. 

1. Tests of various kinds of electric railway motor equipments under 
constant load, regulated by brake, to determine rate of heating — 

(a) Of the armatures. 

(b) Of the field coils. 

2. Tests of electric railway motor equipments, of the various kinds, 
to determine the motor efficiency under different fixed conditions of 
operation^ including varying number of stops per mile. 



INTRODUCTION 11 

3. Tests on motor equipments to determine their torque curves and 
accelerating power. 

4. Tests on electric railway motor equipments under constant loads 
to determine the rheostatic losses corresponding to various lengths of 
time consumed in application of full current strength. 

5. Tests on electric railway motor equipments to determine at what 
loads, speeds, and frequency of stops it becomes economical to adopt 
automatic control in place of hand control for single cars. 

6. Tests on hand, automatic, and multiple control systems to deter- 
mine their relative economy, certainty, and regularity of starting motor 
car equipments under fixed conditions of load and track. 

7. Tests of electric railway motor equipments to determine safe load 
during continuous operation, as compared with rated capacity of motors. 

Tests of Electric Railway Equipments on Experimental Track. 

8. Tests to determine the relative value of two-motor and four-motor 
car equipments: 

(a) As to power consumption : 

1st — With fixed load. 
2d — ■ With varying load. 

(b) As to acceleration : 

1st — • With fixed load. 
2d — With varying load. 

9. Tests to determine the proper method of mounting a two-motor 
equipment on an eight- wheel two-truck car, viz. : On which two of the 
four axles shall the motors be mounted? 

10. Acceleration tests on single cars and on motor car and trailer, 
showing : 

(a) Rate of acceleration: 

1st — Hand control. 

2d — Automatic control. 

(b) Power used: 

1st — Hand control. 
2d — Automatic control. 

11. Comparative tests on different types of power brakes, both 
electrical and mechanical, in respect to: 

(a) Efficiency. 
(6) Economy. 

12. Braking tests on single car, and on motor car with trailer, under 
varying conditions: 

(a) With hand brakes. 

(b) With power brakes. 



12 ELECTRIC RAILWAY TEST COMMISSION 

13. Tests on single car equipments to determine motor and truck 
friction at different speeds. 

In the matter of equipments operated by stored power, your Com- 
mittee understands that it is hmited in its considerations to such equip- 
ments as are electrically operated. This excludes all systems of stored 
power, excepting those operated from storage batteries. 

The tests heretofore recommended for electric motors are all applica- 
ble to electric motor equipments operated from storage batteries, as 
also are the controller tests. 

As to the batteries themselves we would recommend the following 
tests : 

14. Tests to determine the efficiency of batteries under — 
(a) Maximum load. 

(6) Average load, 
(c) Varying load. 

15. Tests to determine life of batteries under — 
(a) Average conditions of service. 

(6) Adverse conditions of service. 
Your Committee believes that the tests above recommended cover the 
more important phases of the subject, and that the results obtained, if 
the tests are carried out, will be of undoubted value to the engineers 
and all users of electric railway apparatus. 
Respectfully submitted, 

M. G. Starrett, 
D. F. Carver, 
Wm. S. Twining. 
Committee on City and Suburban Electric Railway Equipments. 

REPORT OF COMMITTEE ON TEST OF INTERUEBAN EQUIP- 
MENTS. 

Anderson, Ind., March 14, 1904. 
Electric Railway Test Commission, 

Universal Exposition, St. Louis, 1904, 
43 Exchange Place, New York City. 
Gentlemen: Complying with your request, we submit herewith a 
report outlining the tests which we believe it would be desirable to 
conduct at the Exposition on high speed and moderately heavy inter- 
urban equipments, bearing in mind the facilities which you will have 
at your command, as outlined in your letter. 

The Committee is well aware of the fact that numerous laboratory 
and shop tests have been made, both by the manufacturing companies 
and the operating companies, and valuable data with respect to the 
characteristics of interurban equipment of all classes is available for the 



INTRODUCTION 13 

use of any engineer or company. We believe that this data is accurate 
within the hmits of the precision of measurements, and it will therefore 
be unnecessary for the Commission to take the time to duplicate tests of 
this character, which cover the following points set forth in the memo- 
randum accompanying your letter of February 1, 1904: 

Tests on Apparatus in Electricity Building. 

(a) Tests on electric railway motor equipments under constant 
load to determine rate of heating during continuous operation. 

(6) Tests on electric railway motor equipments to determine effi- 
ciency of such motors under different fixed conditions of operation. 

(c) Tests on electric railway motor equipments to determine their 
torque curves and accelerating power. 

With reference to your section "d'' as follows: 

(d) Tests of hand, automatic, and multiple control systems to 
determine their relative economy, certainty, and regularity of 

starting motor car equipments under fixed loads. 
We wish to recommend that the tests of systems of control be made 
in conjunction with outdoor tests of railway equipments on the experi- 
mental track, with the possible exception of tests made to determine 
the electrical energy required for operating multiple control systems, 
and that shop tests be made on the different systems of multiple control 
to determine the electrical energy required to bring the control to the 
''full on'' position in different lengths of time, and also the energy re- 
quired to hold the control at "full on" position. With this data, it 
will then be possible to determine the relative economy of the different 
types of control, as well as the total power consumption of any type under 
any given conditions of train operation. 

Tests on Electrical Railway Equipments on Experimental Track. 

We have considered the various classes of cars and equipments which 
seem to come within the field allotted to this Committee, and, realizing 
that the Commission will probably have time to conduct a series of 
tests on only one type of this equipment, we recommend that the experi- 
mental equipment consist of the following: 

Standard interurban car body, weight sixteen to twenty tons, 

exclusive of trucks and motors. 
Standard pair of interurban trucks, weight eight to twelve tons per 

pair. 
Standard direct current railway motor equipment, consisting of 
four seventy-five horse-power motors, with such different types of 
hand and train controlling apparatus as are available. 



14 ELECTRIC RAILWAY TEST COMMISSION 

The above type of car will weigh complete (including car body, trucks; 
equipment, and average live load) from thirty-five to forty tons. 

We note that the experimental tracks at the Exposition will consist 
of two parallel tracks 1,400 feet in length, and two parallel tracks 2,000 
feet in length, and there is a possibihty of obtaining a track three miles 
in length. We feel that the first two lengths of track mentioned are 
not long enough to permit tests that will be found to be desirable, ^and 
recommend that the Commission endeavor to secure the use of the three- 
mile track, as this length of track will make it possible to obtain test 
conditions furnishing data of greater value than may be secured on the 
shorter tracks. 

In general, the three points in regard to which the least accurate in- 
formation is available are: 

(1) The relation between the average electrical losses in the motors 
and the rise in temperature attained under various conditions 
of high speed service. 

(2) The train resistance (or power required to propel a car or train 
at uniform speed) at very high speeds. 

(3) The performance of cars equipped with controller so arranged 
that the acceleration is automatic as compared with the per- 
formance under similar conditions, where the rate of acceleration 
depends upon the handling of the controller by the motorman. 

All information which can be obtained on these three points will be 
exceedingly valuable. The use of the track three miles in length will 
enable the cars to be run at speeds reaching sixty to seventy miles per 
hour as a maximum, and making a schedule speed of thirty-five to forty 
miles per hour. 

Tests of Motor Performance and Rise in Temperature. 

In general, the performance of a car in service can best be represented 
by speed time and current curves, as shown in Fig. 1. 

These curves show at once such items as rate of acceleration, max- 
imum speed, rate of coasting, and rate of braking. 

The power input to the car at any instant is shown by the line vol- 
tage and the current at that instant. The average power used by the 
car can be deduced by averaging the instantaneous power, and may 
be verified by a recording wattmeter. The schedule speed can also be 
deduced from the curve showing instantaneous speeds and can be veri- 
fied by the time and distance. 

The power input when the car is running at any uniform speed gives 
at once the train resistance for that speed. From the current input to 
any motor of the equipment and the voltage at its terminals, the electric 



INTRODUCTION 



15 



50-53C 








Current, Speeld and 


'■■ 1 "1 — 1 
Time Curves. 




















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SChLUL/Ln. orccD 
























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50-500 






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^0-500 




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40 80 1^0 160 200 240 230 520 360' 

SEC ONDS 

Fig. 1. —Currents, Speed and Time Curves. 




Z 3 4 3 6 " 7 

HOURS 

Fig. 2. — Time Temperature Curves. 



16 ELECTRIC RAILWAY TEST COMMISSION 

losses which take place in this motor can be readily found. These in- 
stantaneous losses, averaged for the time of the entire cycle, give the 
average losses which determine the heat input. 

By running the car backwards and forwards, over a given track re- 
peating as nearly as possible each time a given cycle of acceleration 
maximum speed, coasting, braking, and duration of stop, a condition 
similar to actual service is obtained. The temperature of the various 
parts of the various motors can then be measured at intervals until 
these temperatures become constant, which indicates that the heating 
effect of the current introduced into the motors is just balanced by the 
cooling effect due to the speed of the car. A time and temperature 
curve can then be plotted showing the rise in temperature of the motors 
during the run until they reach a constant temperature. Such a curve 
is shown in Fig. 2, 

Since the rise in temperature with given average losses in the motors 
will be largely influenced by the ventilation which will depend largely 
upon the speed at which the cars run, the above operation should be 
carried out at several different schedule speeds with their corresponding 
cycles of acceleration, maximum speed, coasting, braking, and duration 
of stop. Such results will then show for the equipment under test the 
following : 

(1) With a rise in temperature of 55 degrees centigrade above the 
temperature of atmosphere, what average losses (square root of mean 
square current and equivalent voltage) are permissible at schedule 
speeds of 25, 30, 35, and 40 miles per hour, respectively ? 

(2) With maximum average losses allowable in motors at sched- 
ule speed of twenty-five miles per hour {i.e., such as to give temper- 
ature rise of 55 degrees) what will be the rise in temperature with 
schedule speeds of 30, 35, and 40 miles per hour, respectively ? 

Such data will enable the probable performance of an equipment 
under a given service to be more closely estimated in advance than 
is now possible. 

In the above series of tests, the condition which we have in mind 
is one in which the car is kept constantly moving with the exception of 
the comparatively short service stops, and with the exception of the 
time necessary to measure at intervals the temperature of the motors. 

The condition on many interurban roads is such that a layover may 
be had at the end of each run. For instance, the car may lay over half 
an hour at the end of a run of two and a half hours. A second series of 
tests in which the car is run in the same way with such a layover will show 
the effect of this layover on the ultimate temperature attained, and will 
show the increase in average losses which may be allowed and still give 



INTRODUCTION 17 

the same ultimate temperature as was attained when the car was running 
without layover. It is evident that if no heat is added during the half- 
hour layover, the consequent cooling of the motors will permit them to 
withstand greater average losses during the time they are running, than 
they could withstand if running continuously. 

From a series of tests on one size of equipment, as suggested above, 
the performance of other sizes of equipment can be estimated with a 
fair degree of accuracy; but if the equipment and the time are available, 
w^e believe that it would be desirable to conduct tests as outlined in this 
report on cars equipped with both double and quadruple equipments of 
a total capacity of from 200 to 500 horse-power. However, we would 
recommend a complete series of tests and curves, illustrating them, to be 
made with one size of equipment, and the results of these tests analyzed, 
before making tests of other sizes of equipment, as it may be found 
that the average losses which the motors may safely withstand at differ- 
ent scheduled speeds, do not vary sufficiently to make necessary further 
investigation on the subject. 

Tests of Train Resistance. 

Tests should be made to determine the train resistance with single 
cars and with different numbers of cars at various speeds from forty 
miles per hour, upwards, as the train resistance at speeds lower than 
forty miles per hour is fairly well understood. 

Train resistance should be measured in two ways: first, by direct 
measurement of instantaneous power input when running at uniform 
speed, and second, by allowing a car or cars to coast and determining 
the rate of decrease of speed. The effect of different shapes of car front 
should be investigated if possible. The tests should be made if possible 
with one, two, three, and four cars. 

Tests on Hand and Automatic Control Systems. 

Where the object is to compare the relative economy of hand and 
automatic control, it will be sufficient to make tests of single cars. Where 
the object is to compare different systems of multiple control, more than 
one car should be used. 

The effect of the use of automatic acceleration on the power con- 
sumption and the general performance of a car can best be studied by 
plotting complete curves, showing the instantaneous values of speed, 
current, etc., as in Fig. 1. Such curves should be plotted from tests 
on the same car under conditions similar, as nearly as possible, 
with the car equipped at one time with automatic acceleration and at 
another time without automatic acceleration. 



18 ELECTRIC RAILWAY TEST COMMISSION 

A test should also be made to determine the saving of power, if any, 
made by using a mechanical device on hand controllers, to limit the 
rate at which the controller is thrown on. The data derived from such 
tests should show the average as well as the maximum power consump- 
tion at any instant during the cycle, and also the fluctuation of power 
during the cycle, when the resistance in the circuit is varied. From 
this data a comparison of the relative values of this type of control and 
unrestricted hand control may be made. 

Knowing full well the vast amount of experimental work to be done 
at the Exposition, we have confined ourselves to a few suggestions as 
to tests on railway equipments which would furnish data of value from 
a practical standpoint, which data, as far as we know, has not hereto- 
fore been obtained from careful investigation and experiment. 
Respectfully submitted, A. L. Drum, 

Charles Jones, 
C. A. Alderman. 
Committee on Interurhan Electric Railway Equipments. 

REPORT OF COMMITTEE ON TESTS OF HEAVY TRACTION 

EQUIPMENTS. 

New York, U. S. A., April 1, 1904. 
Electric Railway Test Commission, 

Universal Exposition, St. Louis, 
Mr. J. G. White, Chairman, 

43 Exchange Place, New York City. 
Gentlemen: Complying with your request for the submission of a 
program to be followed in the conducting of tests upon heavy traction 
electric railway equipments at the St. Louis Exposition, your Committee 
begs to suggest as follows: 

(1) Each party submitting apparatus for test shall furnish a com- 
plete written description thereof, setting forth clearly the special 
features of the design and calling attention to any points that are 
considered new. The description shall also explain the controlling 
mechanism, designating its applicability to direct or alternating 
current, with proposed working voltage, and if for alternating current, 
stating the frequency and phase desired for most successful operation. 

(2) All tests shall be conducted upon the track designated by the 
Electric Railway Test Commission and conducted under actual oper- 
ating conditions. 

(3) No tests shall be made upon electric locomotives or other 
apparatus of less than 500 normal horse-power unless especially per- 
mitted by the Commission. It is assumed that the term ''Heavy 



I 



INTRODUCTION 19 

Traction" applies to locomotives or motor cars of a total capacity 
rated on an hourly basis of 500 horse-power or more. 

(4) The tests will be conducted with the locomotive or motor 
cars running light and also when pulling trains, with the purpose of 
studying the following features: 

(a) Motor capacity under various conditions of operation. 

(6) Acceleration. 

(c) Coasting. 

id) Braking. 

(e) Heating. 
The following curves and diagrams shall be prepared: 

(/) Speed time curves. 

ig) Distance time curves. 

Qi) Voltage and ampere time curves, 

{%) ICilowatt input and distance curves. 

Draw-bar pull diagrams made when attached to a fixed 
anchor and also with dynamometer coupled between locomotive 
and trains operated under running conditions. 
If alternating current motors are used, the following additional curves 
shall be prepared : 

(/c) Real kilowatt time curves. 

(Z) Apparent kilowatt time curves. 

(5) The tests shall include the determination of heating and the 
distribution of the same in the field, armature, and commutator, 
under various loads at different rates of speed. The heating of the 
bearings shall also receive consideration. 

(6) The tests of the methods of control and comparison of hand 
and automatic acceleration shall be made as bearing upon the elements 
of: 

{a) Safety. 

(6) Convenience. 

(c) Economy. 

(d) Smoothness of operation. 

(e) Ability to group into two or more units. 

(7) The tests of the methods of control shall also be considered as- 
bearing on: 

{a) Smoothness of acceleration. 
(6) Variation of economical speeds, 
(c) Reversibility. 

{d) Action with one or more motors cut out. 
(e) Relation of starting to running current under different rates 
of acceleration. 



so ELECTRIC RAILWAY TEST COMMISSION 

(8) The equipment will be considered as to: 
(a) General construction. 

(6) Weight and distribution of same on drivers under static 
and hauling conditions. 

(c) Relative weights of electrical and mechanical parts. 

(d) Number and size of drivers. 

(e) Acceleration of working parts. 
(/) Influence on track. 

(9) Tests will be made upon each locomotive or motor car sub- 
mitted, to ascertain: 

(a) Watt hours per ton mile with locomotive running light at 

various speeds. 
(6) Watt hours per train ton mile exclusive of locomotive, 
(c) Watt hours per ton mile with locomotive load and with 

train under various weights and acceleration. 

(10) Methods and detail conditions for conducting the tests shall 
be agreed upon by those who have immediate charge of the tests, 
before the commencement of the trials. These conditions shall be 
satisfactory to the representatives of those furnishing the apparatus. 
It is understood that all tests shall be made under similar conditions 
when possible. When these conditions are necessarily dissimilar, due 
allowance shall be made in compiling the results, so as to place all 
apparatus upon the same plane of comparison. 

Frank G. Sprague, 
F. R. Slater, 

W. J. WiLGUS, 

BioN J. Arnold. 
Committee on Heavy Electric Traction. 

EEPORT OF COMMITTEE ON TESTS OF NEW ELECTRIC 
RAILWAY SYSTEMS. 

Chicago, March 8, 1904. 
J. G. White, 

Chairman, Electric Railway Test Commission, 
Universal Exposition, 
43 Exchange Place, New York. 
Dear Sir : Complying with your request to submit an outline of tests 
to be conducted upon new electric railway systems at the St. Louis 
Exposition, your Committee begs to submit the following: 

In general each party furnishing apparatus to be tested shall sub- 
mit a written or printed description setting forth clearly and fully the 
salient points in the system, and the principal advantages claimed for 



INTRODUCTION 21 

it. He will also completely describe the motors and controlling appar- 
atus, stating whether the system is designed for direct current or alter- 
nating current, or both, and if for alternating current whether for single 
phase, multiphase, series, repulsion, induction, synchronous, or other 
type of motor, and state in any case the most desirable voltage to use 
in the motor, and if alternating the preferred frequency. 

In testing any new system we have assumed that the tests should be 
divided into principal parts, as follows: 

1st. Motors, including car equipment. 

2d. Line, including all substation apparatus and other translating 

devices interposed between the power house bus-bars, and the trolley 

wheel or contact shoe of the locomotive or car. 

Schedule of Motor Tests to be made with Apparatus Running Stationary 
upon Testing Blocks : 

(a) Test motors to determine efficiency, power factor (if alternat- 
ing), torque, speed, horse-power, output under various conditions as 
to voltage, frequency (if alternating) and current, to be met in the 
service for which the system tested is intended. 

(6) The one-hour rating of motors to be determined according to 
the standards outlined by the American Institute of Electrical En- 
gineers. 

(c) Test motors under constant loads to determine rate of heating 
during continuous operation. 

Schedule of Tests to he made on Equipment when Operating upon Ex- 
perimental Track : 

(a) Acceleration tests of single cars and multiple equipped trains. 
(h) Braking tests of single cars and multiple equipped trains. 

(c) Coasting tests of single cars and multiple equipped trains. 

(d) Motor heating tests of single cars and multiple equipped trains. 
Prepare the following curves : 

(e) Speed time curves. 
(/) Ampere time curves. 
(g) Volt time curves. 

(h) Real kilowatt time curves. 

(i) Apparent kilowatt time curves (if alternating). 

(f) Distance time curves. 

(k) Tests and curves to determine car and train friction. 

Schedule of Tests to he made upon Line and Auxiliaries : 

Determine : 

(a) Ohmic resistance. 

(b) Inductive reactance. 

(c) Power factor. 



22 ELECTRIC RAILWAY TEST COMMISSION 

(d) Efficiency of copper and iron portions of line, separately and 
jointly, under the following conditions: 

1st. When the electrical energy is delivered from the power house 
bus bars to the working conductor without translating devices. 

2d. When electrical energy is delivered from the power house bus 
bars to the working conductor through supplemental transmission 
lines or translating devices. 

If supplementary transmission lines or devices are used in case No. 
2, each element shall be tested separately as well as in conjunction with 
the line as a whole as outlined above. 

Tests upon each system shall be made to determine the following: 
(a) Watt hours per ton mile at car. 

(6) Watt hours per ton mile at substation bus bars (in case sub- 
stations are used), 
(c) Watt hours per ton mile at power house bus bars. 
All tests to be under like conditions, and when conditions are neces- 
sarily unlike, due allowance shall be made to reduce the apparatus 
tested to a fair basis for comparison. 

The watt hours per ton-mile, as stated above, to be determined from 
the summation of the specific tests hereinbefore outlined, and checked 
by integrating wattmeters placed on the power house bus bars, sub- 
station buss bars (if substations are used), and the car. 

Respectfully submitted, 

BioN J. Arnold, 
Paul M. Lincoln, 
W. B. Potter. 

Committee on New Electric Railway Systems. 



The Executive Committee. 

The preliminary work being well in hand and the field having 
been carefully surveyed by the Engineering Committees, the 
next step was the appointment of the Executive Committee. 
The duties of this committee were to decide upon and to carry- 
out such tests as appeared practicable for the Electric Rail- 
way Test Commission to accomplish. For the purpose of per- 
sonally directing the work, superintendents were selected from 
the instructional forces of technical colleges; their positions 
giving them a neutral attitude toward the product of the man- 
vifacturer. With Professor Goldsborough as chairman, these 



INTRODUCTION 23 

superintendents formed the Executive Committee, which was 
constituted as follows: 

Professor W. E. Goldsborough, Chief, Department of Elec- 
tricity, Universal Exposition, Chairman. 
Professor H. H. Norris, Cornell University, 

Superintendent, Electric Railway Tests. 
Professor B. V. Swenson, University of Wisconsin, 
Assistant Superintendent, Electric Railway Tests. 
Professor H. T. Plumb, Purdue University, 
Assistant Superintendent, Electric Railway Tests. 
Professor Goldsborough took great interest in the work from 
its inception. It was largely due to the active part he assumed 
in furthering the interests of the Commission that the project 
was carried to a successful completion. Professor Goldsborough 
directed the work in general and was consulted on all matters of 
importance. 

Professor Norris began his active duties as superintendent of 
tests on June 15, 1904, and continued his direct supervision 
until February 1, 1905, when it became necessary for him to 
again assume his duties at Cornell University. However, he 
continued to act as superintendent and devoted a very consid- 
erable portion of his time from February to October, 1905, to 
the preparation of the report. 

Professor Swenson became associated with Professor Norris 
in the work of the Commission on June 15, 1904, and continued 
to be actively engaged in the testing work of the Commission 
until its completion on March 22, 1905. From that time until 
October, 1905, he devoted his entire time to the preparation of 
the report. 

Professor Plumb began his active duties on June 15, 1904, 
and continued his direct connection with the work of the Com- 
mission until September 1, 1904, when it became necessary for 
him to resume his duties at Purdue University. However, he 
later devoted a considerable portion of his time to preparing 
for and conducting the tests upon car No. 284 of the Indiana 
Union Traction Company, and to the working up of the data 
then recorded. 



24 ELECTRIC RAILWAY TEST COMMISSION 

The Advisoey Committee. 

In order that the plans of the Executive Committee might 
have the benefit of the criticisms of engineers of the large com- 
panies engaged in the manufacture of electric railway apparatus 
and the construction of electric railways, the following advisory 
committee was appointed by the Commission. 
A. H. Armstrong, General Electric Company. 
Clarence Renshaw, Westinghouse Electric and Manufactur- 
ing Company. 
W. S. Arnold, Bullock Electric Manufacturing Company. 
W. N. Smith, Westinghouse, Church, Kerr & Company. 
These gentlemen were consulted during the progress of the 
work and their suggestions were given careful consideration by 
the Executive Committee. 



The Test Corps. 

All of the experimental work of the Commission, as well as 
the major part of the preparatory and construction work inci- 
dent to these various tests, was performed by the Executive 
Committee with the assistance of a number of young men who 
had graduated from some of the leading technical institutions 
of the country. This working organization of superintendents 
and assistants has been designated The Test Corps of the 
Electric Railway Test Commission. 

As these assistants entered upon the work at different times, 
and as, moreover, their terms of service were not at all uni- 
form, it has been thought advisable to state the duration of 
service in each case. 

Name. University. Term of Sertice. 

William Bradford .... Wisconsin .... June 22, 1904- June 29, 1904 

C, E. Carter Wisconsin .... Aug. 1, 1904-Nov. 1, 1904 

W. J. Crumpton Wisconsin .... Aug. 8, 1904-Dec. 4, 1904 

R. N. Davidson Purdue June 15, 1904-Aug. 5, 1904 

W. E. Dickinson .... Cornell Aug. 1, 1904-Sept. 24, 1904 



INTRODUCTION 



25 



Name. 



Ukiversity 



C. J. Fechheimer. .... Purdue . 

H. B. Foote Cornell . 

R. W. Harris Purdue . 

C. A. Heron Purdue . 

O. A. Kenyon Cornell . 

L. J. Kirby Purdue . 

R. J. McNitt Cornell . 

C. C. Myers ....... Cornell . 

G. G. Post Wisconsin 

Robert Rankin Cornell . 

Hartley Rowe .... Purdue . 

W. A. Rowe Wisconsin 

W. F. Sloan Wisconsin 

W. T. Small Purdue . 

Will Spalding Wisconsin 

J. W. Watson Wisconsin 

O. H. West Purdue . 



Term of Seryice. 
(June 15, 1904-June 29, 1904 
(Aug. 7, 19041-Sept. 10, 1904 
, Aug. 1, 1904-Oct. 3, 1904 
June 15, 1904-June 29, 1904 
Aug. 1, 1904-Sept. 9, 1904 
Aug. 1, 1904-Xov. 23, 1904 
Aug. 1, 1904-Feb. 10, 1905 
Aug. 1, 1904-Xov. 28, 1904 
Aug. 1, 1904-Sept. 10, 1904 
June 15, 1904-Sept. 23, 1904 
Aug. 1, 1904-Oct. 3, 1904 
June 15, 1904- July 16, 1904 
June 15, 1904-June 29, 1904 
June 15, 1904- July 1, 1904 
Aug. 1, 1904-Mar. 11, 1905 
June 15, 1904-Feb. 18, 1905 
Aug. 1, 1904-Sept. 22, 1904 
(July 1, 1904- July 11, 1904 
(Aug. 21, 1904-Mar. 1, 1905 



W. T. Giles, of Anderson, Incl., served the Commission through- 
out the construction work and the tests on the car "Louisiana," 
from November 20, 1904, to March 22, 1905. In February and 
March, 1905, the corps was further supplemented by the services 
of three members of the senior class of Cornell University. 
Their names follow : 

R. A. Wright, Feb. 11, 1905-Mar. 11, 1905. 
C. T. Anderson, Feb. 20, 1905-Mar. 11, 1905. 
R. L. Kingsland, Mar. 4, 1905-Mar. 25, 1905. 

The single exception to the general method of conducting 
tests occurred in those upon interurban Car No. 284 of the 
Indiana Union Traction Company. These tests were made in 
February, 1905, at a time when the regular test corps was fully 
occupied with the special car "Louisiana." 

While the tests on Car No. 284 were carefully outlined by 
Professor Plumb and the other superintendents in consulta- 
tion, the former made all detailed plans and preparations, in- 
cluding the construction of all special apparatus, and arranged 
for eight members of the senior class of Purdue L^niversity to 



26 ELECTRIC RAILWAY TEST COMMISSION 

assist in this work and in the taking of data, the latter to be 
used by them in thesis work. The tests were conducted under 
the direct supervision of Professors Plumb and Swenson. Due 
recognition should be given Professors Plumb and his students, 
not only for the work done in preparation, but also for the very 
considerable labor involved in putting the records of these tests 
into permanent form and in working up many of the results. 
The eight Purdue students associated with the Commission in 
the work done on Car No. 284 were the following 

C. L. Bartholome. M. E. Robbins. W. V. White. 

P. W. Gerhardt. F. M. Tripp. G. R. Zipfel. 

J. J. NeHson. J. E. Ulrich. 



Preliminary Report op the Executive Committee. 

The first meeting of the Executive Committee was held at the 
Palace of Electricity, St. Louis, on May 6 and 7, 1904, and 
resulted in the following report. 

preliminary report of the executive committee of 
the electric railway test commission. 

St. Louis, Mo., May 8, 1904. 
Electric Railway Test Commission, 

Universal Exposition, St. Louis, 1904, 
43 Exchange Place, New York City. 
Gentlemen: After careful study of the reports of the Engineering 
Committees, of the suggestions of the Advisory Committee, and of the 
excellent facilities afforded by the Exposition officials, the Executive 
Committee has decided to undertake the following series of tests: 
(a) Tests of the Service Capacities of Electric Railway Motors. 

Equipments will be operated upon the special tracks at different 
rates and durations of acceleration, coasting and braking, with differ- 
ent durations of stop, in order to determine the heating of the motors 
under conditions approaching as nearly as possible those of com- 
mercial practice. The motors will also be tested separately for heat- 
ing and for the determination of their torque curves and accelerating 
power. This will render possible the comparison of the performance 
of the same equipment upon the track and upon the test stand. 



INTRODUCTION 27 

(6) Acceleration Tests. 

Acceleration tests upon single cars and upon multiple equipped 
trains will be made to determine the ability of the equipment to 
bring the cars up to speed quickly and economically. 

(c) Braking Tests. 

Braking tests upon single cars and multiple equipped trains will 
be conducted in order to determine the quickness of action, the shapes 
of the braking curves, the relation between the braking forces and 
the applied pressures, and the best methods of application of the 
braking forces. 

(d) Tests upon Train Resistance. 

Determinations of the resistances due to the rails, to the journals 
and gearing, and to the air will be made by systematic and complete 
series of runs. The effect of the shape of the car body will be care- 
fully investigated. The methods to be used in measuring train re- 
sistance comprise the use of calibrated motors as the source of power, 
the hauling of the car under test by calibrated dynamometers, and 
by noting the falling off in speed while the cars are coasting. The pres- 
sure of the air upon different parts of the car will be recorded by means 
of self -registering pressure gages. 

In addition to these definite series, a number of other tests will be 
conducted upon various exhibits in the Palace of Electricity in order 
to determine their efficiency and reliability. 

Sections (a) , (6) , and (c) of the tests will be carried on upon the tracks 
which have been built for the purpose by the Exposition. These are of 
substantial construction, conveniently located, and of a total length of 
about 4,500 feet. For the tests described under section (d) the Indiana 
Union Traction Company has provided a stretch of eight miles of straight 
and heavily ballasted track. The resistance tests will be made after 
the completion of the St. Louis program. 

In all the above work, graphical records of the measurements will 
be obtained by the use of autographic instruments which will be either 
built for the purpose or supplied through the co-operation of the manu- 
facturing companies and the technical colleges. The National Bureau 
of Standards will materially aid in the work by providing facilities for 
the calibration of all of the instruments. 

For the purpose of comparison, the various railway equipments will 
be divided into several classes including car weights up to forty-five 
tons, as follows: 

(a) Light city service equipments. 

(b) Heavy city service equipments. 

(c) Light interurban service equipments. 

(d) Heavy interurban service equipments. 



28 ELECTRIC RAILWAY TEST COMMISSION 

The actual work of observation and calculation will be carried on 
under the personal supervision of the superintendents, assisted by a 
corps of young men carefully selected from among the graduates of 
leading technical schools, the total number of observers being between 
thirty and forty. The Exposition management is co-operating enthusi- 
astically with the Railway Test Commission in providing ample facilities 
for the tests, and substantial results of permanent value to the profes- 
sion are confidently expected. 

At the present time a large part of the equipment is already at St. 
Louis, the organization is complete, and the ranks of the testing corps 
have been filled with young men who are already fitting themselves 
especially for the tasks before them. 

Respectfully submitted, 

W. E. GOLDSBOROUGH, 

H. H. NoRRis, 

B. V. SWENSON, 

H. T. Plumb. 



Financial Features of the Work. 

While the work of the Electric Railway Test Commission 
was clone imder the auspices of the Universal Exposition, the 
Exposition authorities did not provide any funds for carrying 
out the project. The Exposition Company did, however, aid 
in a number of ways, such as providing equipments and facil- 
ities for testing. 

In order to defray the cost of maintaining the test corps, as 
well as to meet the many expenses incident to the conduction 
of experimental investigations, a considerable sum of money 
was necessary. This will be very readily understood when it 
is remembered that the experimental work began June 15, 
1904, and was not completed until March 22, 1905, and that 
considerably more than a year elapsed from the time the experi- 
mental work began until the work on the Report was finished. 

The funds for carrying on the work of the Commission were 
obtained by means of subscriptions from the various individ- 
uals and companies interested in the tests. These fimds were 
secured by the members of the Commission and the list of sub- 
scribers and subscriptions is given in Appendix B. 



INTRODUCTION ^9 



Co-operating Companies. 

Various manufacturing companies responded most cordially 
to requests for apparatus and instruments to be used in con- 
nection with the tests. The Standardization Laboratory of 
the United States Bureau of Standards proved of very great 
value in connection with the calibration of instruments. Tech- 
nical schools also assisted by the loan of instruments. 

A complete list of the co-operating companies and institu- 
tions is set forth in Appendix B. 

The Tests. 

Although the superintendents and a portion of the testing 
corps assembled for the work at St. Louis on June 15, 1904, it 
necessarily took some time to organize and prepare for the 
actual testing work. 

The Report shows that the tests actually performed by the 
Executive Committee in several instances departed widely 
from those outlined in the suggestions of the Engineering Com- 
mittees. The Executive Committee would have been more 
than pleased to have carried out the wishes of the Engineering 
Committees, but in the instances mentioned it was found im- 
practicable to do so, either because of the hesitancy of manu- 
facturers to permit certain apparatus to be tested or to a lack 
of facilities for testing, and in some instances to both of these 
conditions. 

In outlining the tests it is to be remembered that a large 
amount of preliminary work was necessary in all cases and that 
in. many instances this consumed considerably more time than 
did the actual tests. 

The first tests attempted were those relating to the effects 
of alternating currents upon steel rails. These were begun in 
July and continued until September. All of this work was car- 
ried on in the space of the Bullock Electric Manufacturing Com- 
pany in the Palace of Electricity. 



80 ELECTRIC RAILWAY TEST COMMISSIOI^ 

The next series of tests were those on the compressor station 
of the St. Louis Transit Company at Tower Grove Park, St. 
Louis. These began on the first of August and extended over 
a period of about one week. Following these were the tests on 
the industrial locomotive, which began during the second week 
in August and continued about ten days. They were con- 
ducted in the court of the Palace of Electricity. 

Following these tests were the service tests on Car No. 2600 
of the St. Louis Transit Company, operating on the Park Ave- 
nue Line, St. Louis. These tests began about the middle of 
August and were completed during the latter part of the month. 

Next in order came the stand tests of motor compressors, 
which were carried on during the latter part of August, and the 
first part of September. These tests were made at the Van- 
deventer shops of the St. Louis Transit Company. 

During the progress of the foregoing tests, preHminary work 
was undertaken incident to car tests on the test track just 
north of the Transportation Building. 

The first tests on these tracks were those on the Westing- 
house single-truck car. These tests covered temperature runs 
with magnetic brake, temperature runs with hand brake, ac- 
celeration tests, and braking tests. They began about the first 
of September and continued until the first part of October. 

After the car tests were finished, a number of tests were 
made on the test tracks to determine their electrical conductivity 
and their resistance to alternating currents of various frequen- 
cies. These tests began in October and were completed in the 
early part of November. 

The final tests at St. Louis consisted of some additional motor- 
compressor stand tests which were made at the Vandeventer 
shops of the St. Louis Transit Company, during the first part of 
November. 

During the summer considerable attention had been given 
to the problem of measuring the effect of air resistance 
on car bodies when running at various speeds, and the 
general design of a specially constructed car for these measure- 



tNTRODUCTIOM 31 

meiits had been completed. In addition, various manufac- 
turing companies had shown their interest in the matter by- 
loaning equipment to be used in the construction of this car. 
The Indiana Union Traction Company had agreed to permit the 
work of construction to be carried on in its yards at Anderson, 
Indiana. 

As soon, therefore, as the track tests at St. Louis were com- 
pleted, the test corps and general equipment were transferred 
to Anderson, and active work on the construction of the " Loui- 
siana" was begun about the middle of November, 1904. This 
work occupied over two months, and the preliminary tests 
were made the latter part of January, 1905. After some changes 
and adjustments, the final tests on this car were begim on Feb- 
ruary 6, 1905, and completed March 22, 1905. 

During the months of December and January the prepara- 
tions for the tests of Car No. 284 of the Indiana Union Trac- 
tion Company had been under w^ay. These tests were made 
dm"ing the first part of February, 1905, and they occurred 
between the preliminary and final tests on the car "Louisiana." 



The Report. 

It was the original intention of the Executive Committee to 

work up each test as it was completed. By this method the 

Report would have been practically finished as soon as the last 

-est had been made. Unfortunately, the reduction in the test 

iorps necessitated by financial reasons prevented the accom- 

)lishment of this aim. However, a considerable amount of 

rork was done during the testing period in working up data 

nd putting them into permanent form for filing and future 

iference. 

While it became necessary for Professor Norris to resume 

.s duties at Cornell L^niversity on February 1, he immediately 

Bcame engaged in making arrangements for the working up 

the Report. LTpon the completion of the air resistance 

sts, Professor Swenson proceeded to Ithaca, N. Y., and active 



32 ELECTRIC RAILWAY TEST COMMISSION 

work on the preparation of the Report began the latter part of 
March, 1905. 

It will be noted that the arrangement of the tests in the Re- 
port is not that of the order in which they actually occurred in 
the experimental work. The progress of the tests was governed 
largely by local conditions, and it has been considered desirable 
to arrange the material in a more logical order in the final 
Report. 



PART II. 
SEEVICE TESTS OF ELECTRIC CARS. 



33 



J 

I 



CHAPTER I. 
SERVICE TESTS OF ELECTRIC CARS. 



Objects of These Investigations. 

The service tests of electric cars were undertaken with a 
number of objects in view. Principal among these were the 
study of the general performance of cars and the making of 
comparative tests of single-truck city cars, double-truck city 
cars, and interurban cars. 

General Performance. 

In the general performance tests the cars were operated, as 
nearly as possible, in accordance with practical schedules. Ne- 
cessarily these schedules had to be repeated in regular routine, 
but they were made under fixed rulings which permitted, to all 
intents and purposes, of the same strain upon the motors and 
the equipments as is ordinarily experienced in the service for 
which the equipments were designed. 

Special Tests on a Single-Truck City Car. 

Special tests were made upon a selected single-truck city car 
for the purpose of obtaining a specific comparison of the con- 
sumption of power and the heating of the motors, (1) when hand 
brakes were employed, and (2) when magnetic brakes were 
employed. 

Special Tests on a Double-Truck City Car. 

It was possible, in connection with the tests upon a double- 
truck city car, to make a special study of the performance of 
the car equipment when operated: (1) on a dry track on a clear 

35 



36 ELECTRIC RAILWAY TEST COMMISSION 

day; and, (2) on a wet track on a rainy day. Comprehensive 
data illustrative of the energy consumption and the heating of 
the motors under these conditions are included elsewherein full. 

Special Tests on an Interurban Car. 

In the special tests made upon an interurban car, the intent of 
comparing the performance of the car, when operated alone and 
when hauling a trailer, was successfully carried out. A variety 
of data on this subject has beeii secured, and is presented else- 
where in the Report. 

Test Conditions. 

In all of the tests, great care was taken to make accurate 
records of the starting and running currents, line pressure, 
power consumption, motor heating, maximum and average 
speeds, number of stops, brake applications, and number of 
passengers carried; and other important quantities, such as 
average current, average line pressure, kilowatt-hours per car- 
mile and watt-hours per ton-mile, have been derived. 

General Description of the Various Equipments. 

In Part II are included only the results of the car tests which 
are general in character. The tests dealing specifically with 
acceleration and braking are treated of in Parts III and IV. 
In Part II only such reference is made to acceleration and brak- 
ing as is necessary to explain the performance of a car when 
operated in accordance with a given schedule. 

"Service Tests" have been primarily considered to be those 
furnishing data on the general performance of a car operated 
continuously upon a given schedule. The subject-matter de- 
scriptive of these tests includes a complete description of the 
cars tested. The schedule under which each car is operated 
is given in each case, as is also a detailed description of the events 
of each test. 



SERVICE TESTS OF ELECTRIC CARS 37 



THE SINGLE-TRUCK CITY CAR. 

The car body, truck and general equipment, exclusive of 
motors, controllers, magnetic brakes and car wiring, were 
furnished by the St. Louis Car Company. The motors, con- 
trollers, magnetic brakes and car wiring were the product of 
the Westinghouse companies. A general view of this type of 
car is shown in Fig. 3. The body is of the semi-convertible 
type. Some of the general dimensions and data are the 
following : — 

Length over corner posts .... 21 feet. 

Length over bumpers 32 feet 11 inches. 

Length of platforms inside of das!i . 5 feet inches. 

Height of car floor from rails ... 2 feet 11 inches. 

Height of car roof from rails ... 11 feet 10 j inches. 

Width over all 8 feet 8f inches. 

Weight of car body 9,600 pounds. 

Weight of truck 6,500 pounds. 

Weight of two motors 6,000 pounds. 

Weight of general equipment . . . 2,565 pounds. 

Weight of car complete 24,665 pounds. 

Wheel base of truck 7 feet. 

Diameter of wheels 33 inches. 

Number of motors 2 

Horse-power rating of each ... 55 

Seating capacity 32 

Capacity (crowded) 60 



The electrical equipment consists of two No. 56 motors and 
two Type B 23 controllers. The braking equipment was sup- 
plemented by the standard hand brake apparatus of the St. 
Louis Car Company. 

This car was exhibited at the St. Louis Exposition jointly by 
the St. Louis Car Company and by the Westinghouse companies, 
the principal features for exhibition from the standpoint of the 
Westinghouse companies being the magnetic brake equipment. 



38 



ELECTRIC RAILWAY TEST COMMISSION 




CO 



Ji 



SERVICE TESTS OF ELECTRIC CARS 39 

The Car Body. 

The car body is one of the standard 21 foot semi-convertible 
type of the St. Louis Car Company. Fig. 4 shows the general 
detail features of the car. 

The side sills are in two parts of yellow pine, the outer sills 
2 J inches by 7 inches and the inner sills 5| inches by 7 inches. 
The inside side sills are made in two parts with a 7-inch "I" 
beam securely bolted between them. All posts and rails are 
of white oak. The corner posts are 3| inches by 6 inches, and 
the side posts are 2^ inches. 

The platform sills are of 2^-inch white oak, and the middle 
sills are plated with steel plate J-inch by 5 inches. The bumpers 
are 2|-inch white oak faced with -o-inch by 5-inch steel plates. 
The platforms are constructed with entrances on both sides. 
Each end is equipped with a permanent vestibule with double 
folding doors on each side. The steps are malleable iron hanger 
with wood tread covered with safety treads. The hand brake 
consists of l|-inch brake staffs of Norway iron, provided with 
St. Louis Car Company's ratchet bronze brake handles at the 
top and twist brake chains at the bottom. 

The roof is monitor type for the full length of the car body, 
with eight ventilator sashes on each side. The doors are of the 
double automatic sliding type with drop sash. The windows 
are so constructed that both sashes may be dropped. The sides 
of the car have straight paneling of 1-inch poplar, dressed to 
|-inch, to come over the sill plate. The inside paneling extends 
to the floor. The sides of the car are fitted with five window 
guards. The flooring is yellow pine, and the inside paneling is 
mahogany. The car is fitted with the usual motorman's gongs, 
conductor's signal bells, and passengers' push-button signals. 
There are eight St. Louis Car Company's latest type of seats on 
each side, rattan finish. The car is provided with curtains on 
spring rollers, and is thoroughly up to date in all appointments. 



40 



ELECTRIC RAILWAY TEST COMMISSION 




"t> 



•2* 



SERVICE TESTS OF ELECTRIC CARS 



Truck and Running Gear. 



41 



The truck of this car was also built by the St. Louis Car Com- 
pany and is of the No. 9 type of the LaClede works. A photo- 
graphic view of this type of truck is given in Fig. 5, and it is 




Fig. S. — Photogyaph of Truck of the Single-Truck Car. 

further illustrated by the sketches shown in Fig. 6. 
the general dimensions and data are the following: 

Gage of wheels 4 feet 8.5 inches. 

Height of side sills above 

rail without car body . 28.25 inches 

Wheel base 7 feet. 

Weight of truck .... 6,500 pounds. 

Axles, diameter at center. 4 inches. 
Axles, diameter at wheel 

seat 3.5 inches. 

Type of motor suspension, nose. 

Wheels, cast iron, diameter 33 inches. 

Journals 3.5 inches by 5.5 inches. 



Some of 



Motors. 

The driving equipment consisted of two Westinghouse No. 
56 motors. The Westinghouse Company recommends this 
equipment for city service for the operation of either single or 
double-truck cars of any size up to 35 or 40 feet over all, and 
weighing, without equipment or load, from 23,000 to 30,000 
pounds. As previously stated, the car under consideration had 
a gross weight, without load, of 24,605 pounds. The manu- 
facturers further state that in city service, with runs averaging 



i2 



ELECTRIC RAILWAY TEST COMMISSION 




fi 



<II 



^ 




I 



_ 



SERVICE TESTS OF ELECTUIC CARS 43 

from one eighth to one quarter of a mile in length, the equip- 
ment with a gear ratio of from 14 to 68 or 16 to 66, will produce 
an ultimate speed of from 18 to 20 miles per hour approximately, 
on a straight level track with a line pressure of 500 volts. 

The gear ratio on the car tested was 18 to 64, and the length 
of run averaged 790 feet, or about 0.15 of a mile. The ultimate 
speed reached in the tests was approximately 21 miles per hour. 
A general view of this type of motor is shown in Fig. 7. 



Fig. 7. — General View of Westinghouse No. 56 Motor. 

General Description. — Fig. 8 shows a view with the motor 
open, the armature being contained in the lower field casting. 
The field frame of the motor is made of cast steel and is approxi- 
mately cylindrical in shape. It is divided into two parts in a 
plane through the center of the armature shaft and the center 
of the car axle. All the working parts of the motor are inclosed 
by the field castings and thus protected. The poles are built up 
of sheet steel punchings riveted together between wrought iron 
end-plates, the completed pole pieces being bolted to the frame. 
The field coils are wound with asbestos covered round wire, and 
are treated with a special compound to render them moisture 
proof. The armature is of the ventilated slotted drum type, 
14 inches in diameter. It is built up of sheet steel punchings 



44 



ELECTRIC RAILWAY TEST COMMISSION 



assembled and keyed on a steel shaft and clamped between 
malleable iron end-plates. There are 39 slots and 117 coils, i.e., 
three coils per slot. At the pinion end the winding is made 
entirely open, for purposes of ventilation. The commutator is 
10 J inches in diameter and 4H inches long, and has 117 bars. 

The motors have a nose suspension, and are so constructed 
that the armature may be either dropped with the lower half 
of the field or the latter may be swung down alone for inspection. 
The pinion is of forged steel with machine-cut teeth. The axle 
gear is made of cast steel in two parts which are bolted together 




Fig. 8. — Westingfiouse No. 56 Motor. (Motor open.) 

and keyed to the axle. The diametral pitch is three per inch, 
and the face is five inches. The pinion has 18 teeth, and the 
gear has 64 teeth. The gear case is of malleable iron and is 
cast in two parts, the upper half being bolted to the upper half 
of the field frame, and the lower half is attached to the upper 
half. The weight, complete with gears and gear case, is 3,000 
pounds. Without gears and gear case, the weight is 2,685 
pounds. The weight of the armature, complete with commu- 
tator and winding, is 720 poimds. The weight of a double 
equipment, including motors, controllers, diverters, circuit 
breakers, wiring, and other details, is approximately 7,200 
pounds. 



SERVICE TESTS OF ELECTRIC CARS 45 

The Magnetic Brake. 

The power brake, which forms a part of the equipment of the 
car, consists of the magnetic-brake equipment of the Westing- 
house Traction Brake Company. It consists essentially of an 
ingenious combination of a magnetic brake with a wheel brake. 
In braking, the car motors are used as generators, and the 
heaters form the necessary rheostats for controlling the braking 
current. In warm weather rheostats placed under the car are 
used instead of the car heaters. 

The brake proper is illustrated in Fig. 9 and consists essentially 
of (a) a double track-shoe of peculiar construction, combined 
with an electro-magnet which, when energized by the car motors 




Fig. 9. — Westinghouse Magnetic Brake. (Side View.) 

acting as generators, is strongly attracted to the rail; (6) brake 
heads and shoes of the ordinary kind which act directly upon 
the wheels ; and (c) a link mechanism for transmitting the down- 
ward pull and resultant drag of the magnetic brake into a lateral 
pressure upon the wheels. This arrangement of braking appa- 
ratus is in duplicate, so that all four wheels are acted upon in the 
braking. 

The illustration shows the method of attaching the brake 
rigging to the truck, and of suspending the track shoes and 
magnet frames directly over the track. AVhen the brake is not 
in operation, the suspension springs carry the track magnets and 
shoes clear of the rails, and, by means of their flexibility, permit 
the shoes to ride over or clear any obstruction not sufficient to 
cause the car to be stopped. 



46 ELECTRIC RAILWAY TEST COMMISSION 

When the brake is apphed, there are produced four effects, 
all of which assist in bringing the car to rest : (a) The motors 
become generators and receive their energy from the momentum 
of the car, thus the rotative energy of the motors is quickly 
absorbed; (6) The magnets in the track shoes are energized, 
producing a powerful magnetic drag; (c) The drag of these shoes, 
through a system of links and levers, is utilized in pressing 
the ordinary brake shoes against the wheels ; (d) The pull on the 
track shoes also increases the pressure of the wheels upon the 
rails, i.e., it has the effect of increasing the weight of the car. 

Further details concerning the magnetic brake, together with 
the results of the special braking tests in which this brake was 
employed, will be found in Part TV. 

Controllers and Car Wiring. 

The controllers were the B 23 type as manufactured for the 
Westinghouse Company. This type of controller is designed to 
meet the requirements of the magnetic brake. It is intended for 
two 60 horse-power motors, and is provided with sixteen 
notches, five of which are for the series operation of the motors 
and four for their parallel operation, while the remaining seven 
notches are for the control of the magnetic brake. The general 
connections of the motors and resistances at the various posi- 
tions of the controller, are shown in Fig. 54, Chapter V. 

THE DOUBLE-TRUCK CITY CAR. 

This was Car No. 2600 of the St. Louis Transit Company (now 
The United Railways of St. Louis). It was practically new at 
the time the teste were made, having been placed in service only 
for the purpose of limbering up preparatory to the tests. A 
general view of the car is shown in Fig. 10. 

The car body was built by the St. Louis Car Company, and is 
similar to a number of others supplied to the St. Louis Transit 
Company. It is a single-ended, semi-convertible car, with rear 
platform extra long, Detroit style, without vestibule. 



SERVICE TESTS OF ELECTRIC CARS 47 

The trucks were Type No. 25, built by the St. Louis Transit 
Company, which constructs its own trucks. They were somewhat 
similar to the Type No. 24 trucks of the St. Louis Car Company. 

The electrical equipment consists of four General Electric 
Company No. 54 motors and one General Electric Company 
Type K 28 controller. The loop system is in use in St. Louis, 
and the cars have single-ended equipments. 

The air-brake apparatus was not the same in all service tests. 
In the first and second tests the Christensen individual motor- 
compressor system was installed, while in the third test this was 
replaced by the Westinghouse equipment for operation on the 
storage-air system. The braking equipment was supplemented 
in all tests by the standard hand brake of the St. Louis Car 
Company. Some of the general dimensions and data are the 
following : — 

Length over corner posts .... 33 feet 4f inches. 

Length over bumpers 44 feet 8 inches. 

Length of front vestibule .... 3 feet 8 inches. 

Length of rear platform 9 feet. 

Length (center to center of king bolts) 19 feet 10 inches. 

Height of car floor from rails ... 3 feet 2| inches. 

Height of car roof from rails ... 12 feet 3 inches. 

Width over all 9 feet. 

Weight of car body 15,000 pounds. 

Weight of two trucks 13,000 pounds. 

Weight of four motors 7,324 pounds. 

Weight of general equipment . . . 4,676 pounds. 

Weight of car complete 40,000 pounds. 

Wheel base of trucks 4 feet 6 inches. 

Diameter of wheels 33 inches. 

Number of motors 4 

Horse-power rating of each ... 25 

Seating capacity 48 

Capacity (crowded) 120 

The Car Body. 

These cars were built specially for the St. Louis Transit 
Company. As seen from Fig. 10, the car body has the channel 
steel side sills peculiar to the St. Louis Car Company's 



48 ELECTRIC RAILWAY TEST COMMISSION 




o 



CO 



0> 



SERVICE TESTS OF ELECTRIC CARS 



49 



patented construction which allow the windows to be lowered 
between the channels, thus permitting of a lower window sill 
construction than usual. 

The front platform is very short, as it is intended to be occupied 
by the motorman only, although used as an entrance and exit. 
The car body is unusually wide, being nine feet over all, which 
is the widest car body in use in any of the large cities of the 
country. 

Fig. 11 shows views of the rear platform and of the interior- 
The rear platform is seven feet long and represents the extreme 




Fig. 11. — St. Louis Transit Company Double-Tfucf< Cat. 

development of the Dupont type. It is divided into three parts 
by two iron-pipe hand rails built up for the support of the 
passengers. These hand rails do not extend clear across the car, 
but permit of the passengers moving around the ends from one 
part of the platform to another. Fig. 12 shows the general 
detail features of the car. 

" The bottom sills are of steel channels with narrow siding. The 
side and end sills are of the standard channel construction of the 
St. Louis Car Company. All flooring is tongued and grooved, and 
the platform floors are laid with square joints screwed to tlie 
platf^ :m knees with flat head counter-sunk steel screws. 



50 ELECTRIC RAILWAY TEST COMMISSION 

In the body all framing members are mortised to each other. 
All parts are tenoned and draw-pinned into the bottom sills and 
top rails with hickory pins, and the posts are also secured to the 
bottom sills by hack strap bolts. 

The roof framing is constructed in the same general manner 
as is the body framing. Steel carlines are bolted to each rafter 
opposite the side post, and are attached to the top sill plates by 
screws. The bonnet framing also is made up in the same manner, 
and the bonnets are built on formers, the hood bow being of green 
ash, steam bent to shape. The roof is monitor type for the full 
length of the car body, with thirteen ventilator sashes on each 
side. 

The doors are of the single sliding type with drop sash, the 
front doorway being 31 J inches wide while that at the rear is 36} 
inches wide. The windows (thirteen in number on each side) 
are made in two sections, and are so constructed that both 
parts may be dropped below the arm rail. The car is provided 
with curtains on Burrowes fixtures. All inside paneling is of 
mahogany. 

The car is fitted with the usual motorman's gages, conductor's 
signal bells, and passengers' push-button signals. There are 
eleven of the St Louis Car Company's latest type of cross- seats 
on the left-hand side and ten on the right-hand side. There are 
also two seats at the rear of the car to fill the remaining space, 
making twenty-three seats in all. The two rear seats hold 
three passengers each, and the total seating capacity is forty- 
eight passengers. 

Thpre are two sand boxes, also of the St. Louis Car Company's 
pattern. The sand-operating device consists of a vertical lever 
mounted on the platform, the same fixture also carrying a second 
lever for use in operating the fenders. These levers have an 
angle iron stop which also carries the fender lifting lever. The 
hand brake staff is made of If-inch round Norway iron, and is 
provided with a ratchet brake wheel at the top, and a twist brake 
chain at the bottom. 



SERVICE TESTS OF ELECTRIC CARS 



ci 



I 

C5 






sa 




52 



Electric railway test commission 



Trucks and Running Gear. 
The trucks of this car are of the No. 25 double-truck type, 
built in the shops of the St. Louis Transit Company for its own 
cars. A photographic view of a truck, such as those under 



1 




Fig. 13. — Truck of St. Louis Transit Company, Car No. 2600. 

Car No. 2600, is shown in Fig. 13, while Fig. 14 gives a dia- 
grammatic view of its general construction. 

Some of the general dimensions and data for each truck are 
the following : — 

Gage of wheels 4 feet 10 inches. 

Height of center plate above 

rail without car body . . 2 feet 2| inches. 
Height of side bearings above 

rail, car body loaded ... 2 feet 2} inches. 

Wheel base 4 feet 6 inches. 

Weight of truck 6,500 pounds. 

Axles, diameter at center . . 4 inches. 

Axles, diameter at wheel seat 4 inches. 

Type of motor suspension . yoke. 

Brakes outside hung. 

Wheels, cast iron, plate center, 

chilled tread, diameter . . 33 inches. 

Journals 3^ inches by 8J inches. 



SERVICE TESTS OF ELECTRIC CARS 



53 




54 



ELECTRIC RAILWAY TEST COMMISSION 



Motors. 

The driving equipment consisted of four General Electric 
No. 54 motors. This equipment is one recommended by the 
manufacturer for heavy city service. These motors have a 
rating of 25 horse-power with 45 amperes input and 500 volts 
at the motor terminals. The output is based upon the standard 
rating according to the rules of the American Institute of Elec- 
trical Engineers; that is, the horse-power output giving 75° C. 
rise of temperature, above a room temperature of 25° C. after 




Fig. 15. — General Electric Company, Type 54, Motor. 



one hour's continuous run at 500 volts terminal pressure, on a 
stand, with the motor covers removed. 

The gear ratio of Car No. 2600 was 14 to 67, and in the tests 
the average length of run between stops was 1,097 feet, or 
about 0.21 of a mile. The average speed was 10.27 miles per 
hour. A general view of the motor is shown in Fig. 15. 

General Description. — Fig. 16 shows a view with the motor 
open, the armature being contained in the lower field casting. 
The steel field frame is in the form of a hexagon with rounded 
corners, and is cast in two pieces. It is so arranged that th^ 



SERVICE TESTS OF ELECTRIC CARS 55 

lower frame may be swung down so as to permit inspection or 
repairs of the field or armature. The pieces are built up from 
soft iron laminations, riveted together and bolted to the frame 
through bolts with nuts on the outside. Tlie field coils are placed 
at an angle of 45° from the horizontal, and are held in place by 
pressed steel flanges clamped to the pole pieces. The coils are 
made of asbestos, cotton-covered wire, and further insulated with 
wrappings of varnished cloth and tape. The armature is of the 
iron-clad type and is 11.5 inches in diameter. The core is built 
up of soft iron laminations keyed to the shaft and clamped at 
each end by cast iron heads, which are also keyed to the shaft. 
The core is hollow, and is ventilated by the air which enters the 
pinion end of the core and passes out through the air ducts 
placed at regular intervals among the laminations. The arma- 
ture winding is of the series drum type, and has 115 coils of 3 
turns each, and 115 commutator bars. The commutator has a 
diameter of 8^ inches with a wearing length of 3J inches. 

The motors have a yoke suspension, and are so constructed 
that the armature may be either dropped with the lower half 
of the field, or the latter may be swung down alone for inspec- 
tion. The gear ratio is 14 to 67, the pinion and gear both 
being of steel. The latter is made of cast steel in two parts 
which are bolted together. Both gear and pinion have a face 
of 4J inches, and the diametral pitch is three per inch. The 
gear case is of malleable iron and is cast in two parts, the 
upper half being bolted to the upper half of the field frame, 
and the lower half attached to the upper half. 

The weight of a General Electric 54 motor complete with gears 
and gear case is 1,831 pounds. AVithout axle gear and gear case 
the weight is 1,536 pounds. The weight of the armature and 
pinion complete is 395 pounds. The weight of the motive power 
equipment, including four motors, one controller, and the neces- 
sary car wiring, starting resistance, circuit breaker and other 
details, is approximately 8,250 pounds, 



I 



56 



ELECTRIC RAILWAY TEST COMMISSION 



Controller and Car Wiring. 

The controller was of the K 28 type manufactured by the 
General Electric Company. This form of controller is designed 




Fig. 16. — General Electric Company, Type 54, Motor. 

to meet the requirements of a four-motor equipmentof 25 horse- 
power each. It is provided with ten notches, five of which are 
for the series parallel operation of the motors, while the remain- 
ing five notches are for the parallel operation of the motors. 



SERVICE TESTS OF ELECTRIC CARS 



67 



The Air Brake Equipment. 

In the service tests of August 19 and August 24, the Christensen 
individual motor-compressor system of air braking was installed 
upon Car No. 2600, while in the test of August 29 the AVesting- 
house storage-air system of air braking was employed. The brak- 
ing tests on Car No. 2600, which are considered in Part IV, were 
made at the same time as were 
the service tests on this car, and 
it was for the purpose of com- 
paring the two braking systems 
that the braking equipment em- 
ployed in the tests of August 19 
and August 24 was replaced by 
a different system in the tests of 
August 29. 

In the Christensen individual 
motor-compressor system of air 
braking a combination air com- 
pressor and electric motor is 
carried on the car. This motor 
compressor consists essentially 
of a series wound motor and a 
duplex single-acting compressor 
with two pistons which are 
connected by wrist pins to the 
connecting rods engaging with 
the crank shaft. This crank 
shaft is mounted in bearings 
provided in the case, the ex- 
tended end of the crank shaft 

carrying a helical gear which engages with a helical pinion 
mounted in the extended end of the armature shaft of the 
motor. The latter is mounted directly above the compressor, 
the motor base forming a top cover for the compressor. This 
arrangement enables all the working parts to be run in oil. 




Fig. 16 A. — General Electric Company, K. 28, 
Controller. 



58 ELECTRIC RAILWAY TEST COMMISSION 

The armature bearings are specially designed to prevent the 
oil from getting into the armature. 

The Christensen governor consists essentially of an ordinary 
Baurdon pressure gage mechanism with a special hand, which, 
upon coming in contact with a conducting stud at the position 
of minimum pressure, allows current to flow through a solenoid 
magnet which actuates a switch closing the motor circuit. In 
like manner, when the high pressure is reached, the hand comes 
in contact with a second contact stud which operates a second 
magnet coil which causes the switch to be opened. The high 
and low pressure points are adjustable. 

In the test of August 29 when the Westinghouse storage system 
of air braking was employed, the braking equipment in general 
was not disturbed. The Christensen motor-compressor and its 
accompanying reservoir were removed and the storage tanks of 
the Westinghouse system substituted. The piping, engineer's 
valves and gages, and other auxiliary appliances were neces- 
sarily different in the two systems. 

The AVestinghouse storage system of air braking is described 
in detail in Part IV, as is also the individual motor-compressor 
system. In this part the braking equipment is considered in 
detail, so that it will be unnecessary to consider these matters 
further at this point. So far as the service tests on Car No. 2600 
are concerned, it is sufficient to have a knowledge of the braking 
equipment in general and to be familiar with the conditions under 
which this equipment was operated in each test. 

THE DOUBLE-TRUCK INTERURBAN CAR. 

The car tested was No. 284 of the Indiana Union Traction 
Company. The car body and its equipment were furnished by 
the Cincinnati Car Company, the trucks and running gear were 
built by the Baldwin Locomotive Company, while the motive 
power and braking equipments were the product of the Westing- 
house companies. This car was exhibited at the St. Louis 
Exposition by the Cincinnati Car Company and at the close of the 



SERVICE TESTS OF ELECTRIC CARS 59 

Exposition it was turned over to the Indiana Union Traction 
Company. It was built for limited service on the lines of the 
Indiana Union Traction Company. It has a large passenger 
compartment in the rear and a smoking compartment in the 
front, and is supplied with buffet, heater-room, and toilet-room. 
The car was equipped with four No. 85 Westinghouse motors 
controlled by the Westinghouse pneumatic system of train 
control. The air brakes are also of the Westinghouse type. 

A photographic view of the exterior of this car is shov^ii in 
Fig. 17, and the interior is shown in Fig. 18. 

Some of the general dimensions and data are the following: 

Length over corner posts .... 41 feet 6^ inches. 

Length over bumpers 53 feet 5^ inches. 

Length over vestibules 51 feet 3 inches. 

Length (center to center of king- 
bolts) 29 feet 6h inches. 

Height of car floor from rails ... 4 feet 1 inch. 

Height of car roof from rails ... 13 feet 6 inches. 

Width over all 9 feet 1^ inches. 

Weight of car body (equipped) . . 37,400 pounds. 

Weight of two trucks 19,130 pounds. 

Weight of four motors 18,000 pounds. 

Weight of car complete 74,530 pounds. 

Wheel base of truck 6 feet. 

Diameter of wheels 37^ inches. 

Number of motors 4 

Horse-power rating of each ... 75 

Seating capacity 48 

Capacity (crowded) 150 



The Car Body. 

Car No. 284 is one of twenty which were constructed for the In- 
diana Union Traction Company by the Cincinnati Car Company, 
in accordance with the general designs of Mr. John L. Matson, 
superintendent of motive power of the former company. Their 
construction is quite a departure from the usual design, and they 






60 



ELECTRIC RAILWAY TEST COMMISSION 










SERVICE TESTS OF ELECTRIC CARS 



61 



are probably the first electric buffet cars ever put in service on 
regular runs, being used as limited cars on the lines between 
Logansport and Indianapolis and between Muncie and Indian- 
apolis. The first is a run of 79.5 miles, while the latter distance 
is 56.55 miles. Drawings showing the side elevation and the 
general plan of the interior are shown in Fig. 19. 




Fig. 18. —Interior of Car 284, of the Indiana Union Traction Company. 



Experience with similar cars in high speed service having 
shoTVTi the need of a strong bottom framing, these cars were 
constructed with a framing which it is believed will withstand all 
strain to which it may be subjected. The center sills consist 
of two 4-inch by 6-inch steel " I '^ beams, placed 13 inches apart. 
The intermediate timbers are composed of yellow pine 4 inches 



62 



ELECTRIC RAILWAY TEST 'COMMISSION 




ISERVICE TESTS OF ELECTRIC CARS 63 

by 7 J inches. The side sillg are made in three parts; one piece of 
yellow pine 5^ inches by 8 inches, and one piece 2 inches by 7J 
inches, with a |-inch by 7-inch steel plate bolted between and 
running the full length of the sill. Tie rods f-inch in diameter 
are placed along the side of each bridging. 

The single side posts are of ash measuring 2 inches by 4 inches, 
every other post being a pier post consisting of two l|-inch by 
4-inch posts placed 3^ inches apart. 

One of the chief defects of electric cars as usually constructed is 
the tendency to give down in the center and for the platform to 
drop. In the construction of these cars an endeavor has been 
made to overcome this difficulty. In addition to the steel plate 
alongside of the sills, "I" beams of bottom framing and the 
customary plank measuring If inches by lOJ inches, the center 
of the car is supported bytwo trusses. One of these consists of 
|-inch by 2-J inch flat refined iron and is gained into the inside 
of the posts under the belt rail, running the steel strut immedi- 
ately over the bolsters, and from this point it slopes downward 
to enter the side sills terminating in 1 inch round refined iron, 
anchored in a suitable casting. The other body truss consists 
of 1 J- inch by 8- inch ash, gained l|-inch into the outside of the 
posts and runs for a distance .under the belt rail, then descends 
and is mortised into the side sill over the bolster. From this 
point, braces of the same size ascend and are gained into the 
corner posts under the belt rail. 

Each platform timber is supported by steel plates f of an inch 
by 6 inches, bolted securely to the timbers and to the center and 
intermediate sills. In addition to these, there are bolted to the 
outside platform timbers 4-inch by 6-inch angle irons, which upon 
passing under the end sills bend outward and upward to run 
along the side sills to a point beyond the bolsters. The length 
of the front platform from the outside of the end sill to the out- 
side of the sheathing is 4 feet 3 inches, and the rear platform is 
5 feet. Both the car floor and those of the platforms are made of 
Georgia pine, the car floor being laid lengthwise of the car. Each 
end is provided with a bumper of 5- inch oak capped with bumper 



64 ELECTRIC RAILWAY TEST COMMISSION 

irons, those on the side measuring J- inch by 8 inches, and extended 
to follow the curve of the door posts. The front bumper iron is 
I of an inch by 10 inches, and extends so as to lap over the side 
bumper irons. The front end is supplied with a pilot which 
is fitted to the car. The rear end of the car is supplied with a 
Van Dorn No. 11 radiating draw bar, fastened to the platform 
of the car with the necessary supports. The height from the top 
of the rail to the center of the draw bar is 24 inches, and the 
distance from the face of the bumper to the face of the draw is 
8 inches. 

The interior of the car is in dull finished Honduras mahogany. 
There is a large rear compartment, a smoking compartment, a 
buffet, a heater-room, and a toilet-room. The rear compartment 
is provided with Hale & Kilburn reversible seats upholstered 
with deep blue plush; the smoking compartment contains ten 
comfortable wicker chairs. The cars are carpeted throughout 
with Wilton carpet. 

The roof is of the monitor deck pattern, and extends the full 
length of the car, with steam coach type hoods. Steel carlines 
are placed at every double post, and are made in one continuous 
piece from post plate to post plate. The upper deck ceiling is 
made of three-ply bird's-eye maple, in four sections, screwed in 
position every 4 inches. One section is in the forward compart- 
ment and the other three in the rear compartment. 

The upper deck, finished in light blue, is of the Pullman style, 
and its vaulted appearance adds greatly to the lofty effect 
desired. The upper deck sash as well as the upper side sash are 
glazed with opalescent glass, which not only presents a pleasing 
appearance from the outside, but harmonizes well with the 
interior finish. 

All side and end windows are provided with curtains mounted 
on spring rollers. The front doors and windows have curtains 
in the motorman's cab, arranged so as to unroll from the top 
and reaching to the bottom of the glass, thus preventing the 
reflection of light in the vestibule windows at night. 

The buffet is ample in size for the purpose for which it was 



SERVICE TESTS OF ELECTRIC CARS 



65 



It contains a buffet urn, an ice box, cupboards and drawers for 
silverware and dishes. The heater is inclosed in a neat com- 
partment. Space for a coal box is provided by raising the 
heater 12 inches from the floor, thus permitting the coal box to 
be placed underneath the heater. 

The car is provided with a sand box of 3 cubic feet capacity, 
placed immediately in front of the leading wheels. The Nicholas 
Lintern air feed is employed, the control valve being in the 
motQrman's cab and connected to the storage line by ^-inch pipe. 

The hand brake is operated by means of a bevel gear pattern 
20-inch bronze wheel, placed in a perpendicular position. The 




Fig. 20. —Baldwin Locomotive Type Truck for Car 284. 

brake staff is l-]-inch Norway iron, tapered in proportion, and is 
fitted with |-inch twist link chain. 

The air whistle is placed in the roof over the front of the car, 
and is connected to the air pipe system by a J-inch pipe and 
controlled by a valve in the motorman's cab. The car is pro- 
vided with the usual motorman's gong and conductor's signal 
bells. The basket racks are continuous for the full length of the 
car. A water cooler is situated in the forward end of the rear 
compartment. 

The car is equipped with a Mosher headlight, and is also sup- 
plied with an oil'and tool box hung under the car and containing 
two oil cans, one waste can, one coupling bar, two packing irons, 
one wreck rope, two pick-ups, and three flags. A cabinet, con- 



66 



ELECTRIC RAILWAY TEST COMMISSION 



taining emergency tools and provided with a glass front, is placed 
inside the car. A Babcock fire extinguisher is also a part of the 
equipment . 

Trucks and Running Gear. 

The trucks of this car were built at the Baldwin Locomotive 
works. They are of the Baldwin heavy type M. C. B. inter- 
urban trucks with the Gibbs cradle suspension. This is a loco- 




Fig. 21. — General Drawing of Baldwin Truck for Car 284. ^ , 

motive type of truck, and is becoming quite commonly used on 
high speed electric railways. A photographic view of the truck 
is shown in Fig. 20, while Fig. 21 gives a diagrammatic view 
of its general construction. 

Some of the general dimensions and data are the following: 

Gage of wheels 4 feet 8^ inches. 

Height of center plate above 

rail, car body loaded ... 33 inches. 
Height of side bearings above 

rail, car body loaded . . . 36}f inches. 

Wheel base 6 feet. 

Weight of truck 9,565 pounds. 



SERVICE TESTS OF ELECTRIC CARS 67 

Designed to carry on center 

pin 20,000 pounds. 

Axles, diameter at center . . 6.5 inches. 

Axles, diameter at wheel seat . 7.5 inches. 

Type of motor suspension . . Gibbs' cradle. 

Side frames, wrought iron . . 2 inches by 3 inches. 

End frames, angle iron ... 3 inches by 3 inches. 

Pedestals wrought iron. 

Center transom wrouo-ht iron. 

Truck bolster, steel plates . . 9 inches wide. 

Center plate cast iron. 

Equalizing bars wrought iron. 

Spring plank wrought iron* 

Brakes inside hung. 

Bolster springs, double elliptic, . 28 inches long. 

Equalizing springs, single coil, . 7| inches diameter. 
Wheels, cast steel spoke center, 

steel tired 37^ inches diameter. 

Journals 4| inches by 8 inches. 

Journal boxes cast iron. 

Brake leverages 4 to 1 . 

Extreme length of axles . . . 85| inches. 

Motors. 

The driving equipment consisted of four Westinghouse No. 
85 motors. This type of motor is similar in capacity and general 
performance to No. 76 motor of the same company, differing 
from the latter in its mechanical details. 

The manufacturers recommend this equipment for interurban 
service, and state that under reasonable conditions of grade and 
alignment a quadruple equipment of No. 85 motors with 33-inch 
wheels will operate a car weighing from 20 to 25 tons without 
equipment or load at schedule speeds of approximately 25 miles 
per hour, with stops at intervals of 1 J to 2 miles. With 36-inch 
wheels and gears of standard ratio a maximum speed of 45 miles 
an hour may be maintained. 

Car No. 284 had 37-J--inch wheels with a gear ratio of 27 to 47, 
and speeds of over 60 miles an hour were obtained during the 
tests. The average length of run during the service tests was 



68 



ELECTRIC RAILWAY TEST COMMISSION 



3.44 miles, which would correspond to 10.29 stops per mile. 
A general view of this type of motor is shown in Fig. 22, while 
Fig. 23 shows the various parts ready for assembling. 

General Description. — The field frame of the motor is 
made of cast steel and is approximately cylindrical in shape. It 
is divided into two parts in a plane through the center of the 
armature shaft and the center of the car axle. It is so designed 
that when Ih? motor is in position on the truck the holding bolts 
may be taken out and the upper field lifted off. In order to make 
this possible, the suspension lugs and projection for the support 




Fig. 22. — Westinghouse No. 85 Motor. (General View.) 

of the gear case are cast with the lower field. All working parts 
of the motor are inclosed by the field casting. 

The pole pieces are built up of steel punchings, riveted together 
between end plates of wrought iron and are held to tha motor 
frame by bolts. The poles project radially inward at an angle 
of 45° with the horizontal. They are made with projecting 
tips which distribute the magnetism, and also serve to retain 
the field coils which are held in place by spring w^ashers. 

The armature is of the ventilated slotted drum type, and is 
15f inches in diameter. The core is made of sheet steel punch- 
ings built up on a cast iron spider, which is pressed on and keyed 
to the shaft. The commutator is also mounted upon the same 
spider, and the shaft may be removed without disturbing any 



SERVICE TESTS OF ELECTRIC CARS 



69 



other part. There are 39 slots and 117 coils, i.e., three coils per 
slot. The end plate at the pinion end is provided with a bell- 
shaped flange, upon which the windings rest and to which they 
are securely fastened, so as to prevent any difficulty in this 
direction when the motor is running at high speeds. The com- 
mutator is 12 inches in diameter and is 4| inches long, and has 
117 bars. 

The motors have the Gibbs cradle method of suspension, and 
are so constructed that the upper half of the field frame is readily 




Fig. 23. — Westinghouse No. 85 Motor. (Showing Parts.) 

removable. Repairs are made by jacking up the car body, run- 
ning the truck out, and doing all work from above. 

The pinion is made of forged steel with machine cut teeth. 
The gear is made of steel, in one piece, and is pressed on the axle. 
The gear and pinions have a diametral pitch of 2h per inch and 
faces 5 inches wide. The gear case is malleable iron and is in two 
parts bolted together. 

The weight of the No. 85 motor, complete with gears and gear 
case, is 4,500 pounds. The motor alone without gears and gear 
case weighs, approximately, 4,000 pounds. The weight of the 
armature complete with commutator is, approximately, 995 
pounds. The weight of a complete four-m.otor equipment, in- 
cluding motors, one controller, car wiring and usual accessories, 
is, approximately, 21,140 pounds. 



70 ELECTRIC RAILWAY TEST COMMISSION 

Controller and Car Wiring. 

The control equipment consisted of the Westinghouse pneu- 
matic system of train control. In this system the control is 
accomplished by the combined use of electricity and compressed 
air. It consists essentially of a master controller and a turret 
controller. The master controller is operated by hand, and it in 
turn acts on the turret controller. The latter makes the contacts 
for the main current, the master controller using a small current 
only, which is supplied by a storage battery. The master con- 
troller is so arranged that there are but two positions in which 
it can be placed for either forward or backward operation of the 
car. These positions correspond to the series and the parallel 
notches on the ordinary controller. 

If the controller is placed at the series position the master con- 
troller will cause the turret controller to make all of the contacts 
in their order up to the full series position. If the master con- 
troller is placed at the full parallel position the turret controller 
goes through all of the positions in consecutive order up to the 
full parallel position of the ordinary controller. The various 
contacts are made entirely automatically, and the speed at which 
they are made is regulated by the current which the car takes. 
A governing solenoid permits a new contact to be made only 
after the current has been reduced to a certain value which may 
be determined in advance. This method of train control is 
described in detail in Part III, Acceleration Tests. The general 
connections of the motors, resistances and brakes at the various 
positions of the controller, are shown in Chapter IV. 

The Air Brake Equipment. 

The air brake equipment consists essentially of the individual 
motor-compressor straight air brake system as furnished by the 
Westinghouse Air Brake Company. It is similar in general 
principle and arrangement to the Christensen air brake equip- 
ment used in Car No. 2600 of the St. Louis Transit Company's 
lines. 



SERVICE TESTS OF ELECTRIC CARS 71 

Recording Devices. 

Various devices for graphically recording current, speed, 
pressure, and distance traveled, were employed in the different 
tests made upon electric cars. As the method used in obtaining 
these records, as well as the apparatus employed, differed in the 
several tests, it has been considered advisable in general to place 
the descriptions of these devices and methods with the matter 
relating to the specific test where they were first used. The single 
exception to this procedure is in the case of the recording am- 
meter made by the General Electric Company. As this instru- 
ment was employed upon all of the tests upon electric cars (ex- 
cept that of the industrial locomotive), and as, furthermore, 
the records obtained from it have been used so extensively in 
working up the results of the tests, it has been considered ad- 
visable to insert the general description of this instrument here. 

GENERAL ELECTRIC RECORDING AMMETER. 

For the purpose of making records of current which would 
show all of the fluctuations accurately, the recording ammeter 
made by the General Electric Company was selected. This 
instrument (as shown in Fig. 24) consists of the following essen- 
tial parts : 

An ammeter with powerful torque; 
A recording device ; 
A time-marking device. 

The ammeter has for its essential feature a strong magnetic 
field produced biy the current to be measured and proportional 
thereto. The current flows through a few rectangular turns of 
copper bar, and the range of the instrument may be changed by 
connecting these turns in series or in parallel. When in series, 
the range is 600 amperes, and when in parallel, 1,200 amperes. 
In this magnetic field is supported a movable coil consisting of 
about eighty turns of fine wire and carrying a direct current 
which is maintained at a constant value of one ampere. The 



72 



ELECTRIC RAILWAY TEST COMMISSION 



current for the movable coil is supplied by a storage battery. In 
the same circuit are an adjustable resistance and a sensitive 
indicating ammeter. By means of the resistance the current is 
adjusted by an attendant. The moving coil is suspended by a 
controlling spring at the top, and it is guided at the bottom by a 
small shaft which hangs freely in a bearing when the instrument 
is in use. The coil is protected from excessive vibration by 




Fig. 24. — General Electric Company's Recording Ammeter. 



flexible guides, and it is rendered "dead beat" in its motion by 
means of an eddy-current brake consisting of a copper arm carried 
by the moving coil and swinging in the field of a pair of auxiliary 
electro-magnets. Current is carried to and from the moving coil 
through spiral conductors which exert no appreciable controlling 
effect upon the coil. The movement of the coil is controlled by 
a spiral spring, by the adjustment of which the pointer of the 
instrument may be restored to its proper zero position. 



SERVICE TESTS OF ELECTRIC CARS 73 

The movable coil carries an aluminum pointer, approximately 
10 inches in length, which is hinged horizontally near its center 
in order to give it the necessary flexibility. The two parts of the 
pointer are connected by means of a delicate adjustable spring 
which may be made to support the entire weight of the outer end 
of the pointer. 

The recording apparatus of this instrument consists essen- 
tially of a paper-driving mechanism, a pen carried by the anmieter 
needle, and a time-marking device. 

A powerful spring motor equipment with a sensitive governor 
drives a drum over which passes a roll of paper. The paper is 
unrolled from one spool and wound up upon another by the same 
driving force. Slipping of the paper upon the drum is prevented 
by means of pins upon the edge of the drum which engage in 
perforations made along one edge of the paper. The speed of 
this drum is variable over a wide range. The paper, which is in 
rolls about 65 feet long, is 3 uiches in width, and it is ruled into 
spaces which indicate readings of 50 amperes and 100 am- 
peres, with the low and the high range of the instrument 
respectively. 

The current record is produced upon the paper by a delicate 
pen carried at the extreme tip of the ammeter needle. The pen 
consists of a capillary metal tube, one end of which is bent down 
to meet the paper, while the other is carried back along the 
aluminum needle, and dips into a metal ink reservoir located a 
few inches back from the tip. By siphon action the tube draws 
its supply of ink from the reservoir and makes a very satisfactory 
record upon the paper. 

The time-marking device employs a second capillary pen which 
is vibrated by a small electro-magnet. The current for operating 
this magnet comes from a dry battery, and passes through a con- 
tact maker operated by a clock mechanism. The marking mag- 
net operates a small auxiliary pen at set intervals, usually once 
every five seconds, producing a small mark near the base line of 
the record. The distance between these marks is altered by 
changing the speed of the paper-driving mechanism. In these 



74 



ELECTRIC RAILWAY TEST COMMISSION 



tests the spaces were generally from |-inch to |-inch in width. 
A sample record is shown in Fig. 25. 

The main part of the instrument is momited in a substantial 
case with a glass cover through which its operation may be in- 
spected, and the time-marking clock and relay with the dry bat- 
tery occupy a separate case. The delicate indicating ammeter 




3™- 

o6:IOo 



I "^J ' I I II I i 1 I M 1 I II I I I I I 1 I W^ 

o o6*llo o o o Ji2c 



Fig. 25.— Sample Record from General Electric Company' % Recording Ammeter. 

which is used in maintaining the current in the movable coil at 
its proper value, is carried upon a projection at one end of the 
main case, while the adjusting rheostat is on the rear of the same. 
All parts are arranged for convenient operation, and throughout 
the tests the instrument demonstrated its adaptability to all 
kinds of traction testing. 

It will be noted from the above description that the pointer 



SERVICE TESTS OF ELECTRIC CARS 75 

of the instrument moves in the arc of a circle of approximately 
10 inches radius. The record produced is therefore one of curved 
ordinates. It would be very desirable if the instrument pro- 
duced records with straight line ordinates, but for all practical 
purposes this is not essential, and in these tests the records, 
where necessary, have been transferred to straight line ordinates. 



CHAPTER II. 
SERVICE TESTS OF A SINGLE-TRUCK CITY CAR. 

Objects of the Test. 

The principil object of these tests was to study the general 
performance of a typical single -truck city car when operated 
under normal conditions of service, including such measure- 
ments as those of speed, current, pressure, power, energy, and 
motor heating. The car tested had both hand and magnetic 
brake equipment, so that an opportunity was also afforded to 
study the general performance when operated upon a given 
schedule and employing: (a) hand brake control, and (b) mag- 
netic brake control. 

General Description of the Tests. 

The car selected for these tests was a single- truck car, built 
by the St. Louis Car Company, and equipped by the Westing- 
house Electric and Manufacturing Company. It has been 
described and illustrated in Chapter I. 

All of the service tests upon this car were carried out on the 
tracks provided for the Electric Railway Test Commission by 
the Louisiana Purchase Exposition Company, the car being 
operated forward and backward on the shuttle system. As 
previously stated in the Introduction, these tracks were each 
about 1,200 feet in length, and were located parallel to and 
directly north of the Transportation Building at the St. Louis 
Exposition, and are more fully described in Part VI. All 
tests were conducted on the north one of these tracks, which 
was tangent and level for the entire stretch used in the service 
tests. 

76 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 77 



Synopsis of Results. 

Table I. — Synopsis of Besults of Service Tests on Single-Truck City Car. 



Average line pressure (volts) ^ . . 
Average current (amperes) ^ . . . 
Maximum current (amperes) ^ . . 
Square root mean square current 

(amperes) ^ 

Average power (watts) ^ . . . . 
Maximum power (watts) . . . . 
Length of run (feet) .....' 
Time of run (start to stop, second^), 
Time of stop (seconds) ^ . . . . 
Time of run (start to start, seconds). 
Average speed (miles per hour)^ , . 
Maximum speed (miles per hour) 
Schedule speed (miles per hour)^. . 

Stops per mile 

Average watt-hours per run . . 
Average K.W.-hours per car mile . 
Average watt-hours per ton mile 
Average braking current (amperes)^ 
Maximum braking current (am- 
peres)^ 

Square root mean square braking 

cm-rent (amperes)^ . . . . . 
Average power per run (start to stop, 

watts)2 

Average power per run (start to start, 

watts) 2 

Average time of run for day (all 

stops, seconds) * 

Average power for day (all stops 

watts) * 

Total time of day's run (hours)*. 
Temperature rise of motors (°C 

above 25°) ^ 



Test 
No. 1. 



525.8 
117.0 
204.0 

124.1 

61520 
107300 

792 

39.0 
15.0 
64.0 
13.9 
20.8 
10.0 
-6.7 
359 
2.39 
167 



33200 

23950 

59.3 

21800 
8.6 

36.9 



Test 
No. 2. 



520.0 
115.5 
198.0 

121.5 

60060 

102000 

792 
37.0 
15.5 
52.5 
14 6 
20.7 
10.3 

6.7 

350 
2.35 

164 
50.6 

90.0 

60.3 

34100 

24000 

61.6 

20455 

5.7 

35.1 



Test 
No. 3. 



511.2 
116.0 
199.0 

122.0 

59299 

101000 

792 
36.8 
14.9 
51,7 
14.7 
20.0 
10.5 

6.7 

343 
2.30 

16] 
58,0 

112.0 

71.3 

33600 

23884 

62.3 

19820 
7.6 

33.4 



Test 
No. 4. 



514.0 
121.0 
204.0 

124.0 

62194 

105000 

789 

39.0 

11.0 

50.0 

13.8 

20.8 

10.8 

6.7 

338 

2.27 

159 



31200 

24336 

64.1 

19000 
6.8 

33.2 



Test 
No. 5. 



527.2 

116.8 
200.0 

123.2 

61577 

103400 

789 
37.0 
13.0 
50.0 
14.5 
20.9 
10.8 

6.7 

334 
2.24 

157 
50.5 

130.0 

69.2 

32500 

24100 

66.6 

18054 

6.8 

33.1 



AV. OF 

THE 5 

Tests. 



519.6 
117.3 
201.0 

123.0 
609.30 
103740 

791 
37.7 
13.9 
51.6 
14.3 
20.7 
10.5 

6.7 

345 
2.31 

162 
53.0 

110.7 

66.9 

32920 

24054 

62.8 

19826 
7.1 

34.34 



Test No. 1. Sept. 23, 1904, hand brake, dry track. 

Test No. 2. Sept. 24, 1904, magnetic brake, wet track. 

Test No. 3. Sept.'26, 1904, magnetic brake, dry track. 

Test No. 4. Oct. 6, 1904, hand brake, dry track. 

Test No. 5. Oct. 7, 1904, magnetic brake, dry track. 

^ For time power was taken. 

2 For regular schedule. 

^ For time of braking. 

* Including stops for temperature readings. 

^ Average of fields and armatures by resistance. 



78 



ELECTRIC RAILWAY TEST COMMISSION 



It was originally planned to make two service tests of the 
single- truck car, each test continuing throughout a day, or 
luitil the temperatures of the motors had attained constant 
values. One of these tests was to be with the hand brake 
control and the other with the magnetic brake control. Five 
tests of this nature were finally made as shown in the following 
schedule. 

SCHEDULE OF SERVICE TESTS ON SINGLE-TRUCK CITY CAR. 



Test. 


Date. 


Bbake Used. 


No. 1 . . . 

No. 2 . . . 
No. 3 . . . 
No. 4 . . . 

No. 5 . . . 


Friday, September 23d, 1904 

Saturday, September 24th, 1904 .... 
Monday, September 26th, 1904 .... 

Thursday, October 6th, 1904 

Friday, October 7th, 1904 


Hand Brake 
Magnetic Brake 
Magnetic Brake 
Hand Brake 
Magnetic Brake 



Test No. 1. — This was more or less of a preliminary run. 
The data were not as complete as in subsequent runs, and con- 
siderable trouble was experienced in the heating of the axle 
journals of the car. 

Test No. 2. — This run was not entirely satisfactory, be- 
cause the axle journals still gave considerable trouble, and 
because furthermore it began to rain after the test was well 
imder way, and as a consequence the track was wet during a 
considerable portion of the test. 

Test No. 3. — On Sunday, September 25th, the axle journals 
were overhauled by the St. Louis Car people, and the test of 
the 24th was repeated on the 26th. 

Tests Nos. 3 and 4. — Between September 26th and Octo- 
ber 6th a number of acceleration and braking tests were made 
upon this car, the results of which are shown in Parts III and 
IV. When this work was completed, it was thought advisable 
to make two additional service tests before closing the work on 
the single- truck car. This decision was based upon the fact 
that the data taken in the test on September 23d (using the 
hand brake control) were not as complete as desired, and the 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 79 

further fact that the running condition of the car had improved 
since the completion of the first service tests. Consequently on 
Thursday, October 6th, a service test with hand brakes was 
made, and this was followed on Friday, October 7th, with a 
service test using the magnetic brake control. 

THE TOTAL WEIGHT OF CAR. 

The weight of the car equipped and ready for service was 
24,665 lb., as stated in Chapter I. The car had a seating capacity 
of 32 passengers, and it was estimated that 25 passengers would 
be an average load, exclusive of motorman and conductor. 
The total load, on the basis of 150 pounds for each person, 
would be 4,050 pounds. As there were on an average, five 
persons on the car throughout the tests, a dead load of 3,300 
pounds was carried to compensate for the weight of the other 
22 passengers. The main dead load consisted of 20 steel billets, 
weighing 150 pounds apiece, which were placed under the seats 
of the car. The additional weight of instruments and other 
appliances amounted to another 300 pounds, making up the 
necessary total weight, which, under the conditions of test, 
may be summed up as follows: 

Pounds. 

Weight of car equipped and ready for service 24,665 

Weight of total dead load 3,800 

Total average live load 750 

Total 287715 

This total weight is approximately 14.3 tons. 

MOTIVE POWER EQUIPMENT. 

The motive power equipment of this car has already been 
described in a general way in Chapter I. As the service capacity 
of the motors has an important bearing upon the tests consid- 
ered in the present chapter, their characteristic features of 
operation are here briefly discussed. 

General Performance. — The general performance of these 
motors with a gear rat'.o of 18 to 64 is shown in Figure 26. The 



80 



ELECTRIC RAILWAY^ TEST COMMISSION 



curves are taken from data furnished by the manufacturer, and 
show the speed, tractive effort, and brake horse- power, which 
the}' will develop with currents at from 25 to 200 amperes. The 
total electrical power input and the efficiency are also shown. 
The manufacturers made the following statements regarding the 
service capacity of these motors: 

"The motor has a continuous capacity of 50 amperes at 300 
volts, or 46 amperes at 400 volts. Under the usual conditions 



100 40CC 






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Fig. 26. — Curves Showing the General Performance of the Westinghbuse, No. 56 Motor with Gear 

Ratio 18 to 64. 

of railway service, the motor will carry safely an}^ loads within 
the range shown on the curve, provided the integral heating 
effect does not exceed the heating effect which is caused by 
the continuous application of either of these currents at the 
corresponding voltage. 

"In a shop test with either of these loads, the rise in tem- 
perature of the windings of the motor, during an all-day run, 
will not exceed 75° C. as measured by the thermometers. Owing 
to the improved ventilation which is obtained when the motor 



1:>EKVICE TESTS OF A SINGLE-TRUCK CITY CAR 81 

is under a moving car, the temperature rise in service with the 
equivalent of these loads will usually not exceed 55° C. For 
short periods, such as the rush hours, the motor may be operated 
at loads in excess of its continuous capacity. Under these 
circumstances, however, a corresponding increase of temperature 
will result." 

METHOD OF CONDUCTING THE TESTS. 

The first step in planning the tests was to select a schedule of 
operation which would represent average city conditions, as it 
was obviously impossible to cover a wide range of such condi- 
tions within the available time. The number of stops per mile 
selected was 6.7, making a d* stance between stops of 790 feet. 
The cycle of operation performed during each run was as fol- 
lows: 

1. Power turned full on while the car traveled a given dis- 
tance. This averaged 123 feet in Tests Nos. 1, 2, and 3, while 
it was 100 feet in Tests Nos. 4 and 5. • 

2. Power remained on full up to a certain point. This 
averaged 472 feet in Tests Nos. 1, 2, and 3, while it was 390 feet 
in Tests Nos. 4 and 5. 

3. Car drifted with power off, and brakes were applied over a 
distance necessary to bring the car to rest at the proper point. 

In further explanation of these items, it should be stated that 
the power was turned on in a manner such as to produce a 
uniform acceleration while the allotted distance was being 
covered, this operation requiring an average of 8.5 seconds. 

The power was allowed to remain on until a speed of approxi- 
mately 20.75 miles per hour was reached, this being the normal 
speed of the equipment. After a few trials it was found prefer- 
able to allow acceleration over a given distance, which was 
selected as that in which the car reached the speed mentioned. 

Power was then turned off, and the car was allowed to drift 
to a point at which it could be stopped in the allotted distance 
with a normal brake application. Naturally this differed in the 
tests, as it was much easier to stop the car with the power 
brake and it was allowed to drift farther with this than with 
the hand brake. 



82 ELECTRIC HAlLWAY TEST COMMISSION 

The average data corresponding to these test schedules were 
as follows: 



Maximum speed attained (miles per hour) 

Length of run (feet) 

Time of run from start to stop (seconds) 

Time of stop (seconds) 

Time of run from start to start (seconds) 

Average schedule speed (miles per hour) 



20.75 

790 

38 

13 

51 

10.6 



In making the tests, accurate measurements of all quantities 
were taken over a period of about one hour at the beginning, 
one hour at the middle, and one hour at the close of each test. 
These measurements were taken to ascertain the exact condi- 
tions under which the run was being made. At other times 
during the tests, the car was operated systematically in accor- 
dance with the fixed schedule, the time of start and stop being 
recorded for each run. Measurements of motor temperatures 
were made at intervals throughout the test, which was contin- 
ued until the motors had reached a practically constant tem- 
perature. 

OEIGINAL MEASUREMENTS. 

The original data may be divided into three general classes: 
(a) Those relating to speed and distance; (5) those relating to 
the electrical input; (c) those relating to the temperatures of 
the motors. 

Speed and Distance Data. 

Two general methods of measuring and recording speed were 
employed as follows: 

1. A direct-current dynamo with constant field strength, 
belted to the car axle and producing an e.m.f. proportional 
to the speed. A recording device was used with this apparatus. 

2. A Boyer speed recorder belted to the car axle. 

In the first method mentioned, the source of e.m.f. was an 
"Apple" generator. This is a small generator made for igniting 
purposes,^ and it produced an e.m.f. of about ten volts at the 
highest speed which was attained in these tests. It has per- 

* By the Dayton Electrical Manufacturing Company, of Dayton, Ohio. 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 8S 

manently magnetized poles and a supplementary field winding. 
This field winding was connected in series with the moving coil 
of the recording ammeter, the current of which was maintained 
constant at one ampere. By this means an absolutely constant 
field was produced in the small generator used as a speed indi- 
cating device. The generator was mounted on the truck and 
was belted ^ to the car axle. 

The e.m.f . produced by the generator was read upon a Weston 
voltmeter, which indicated an e.m.f. exactly proportional to 
the speed. Frequent calibrations showed that this method was 
perfectly reliable for the purpose of indicating speed within the 
range of the tests. 

As shown in Fig. 27, the voltmeter was mounted in a case 
at one end of a large chronograph, over the cylinder of which 
was passed a wide strip of paper. The paper was unrolled from 
a large spool on one side of the chronograph drum and was 
rolled up on another spool on the other side of the drum. Above 
the chronograph cylinder and parallel with its axis was a pair 
of guides upon which traveled a small pencil carriage. From 
this carriage a cord passed to a small drum mounted upon an 
auxiliary pointer of the voltmeter. This auxiliary pointer was 
mounted directly over the needle of the voltmeter, and the 
movement of the latter was followed by an attendant, who 
manipulated the pointer. By this means there was traced on 
the paper carried by the chronograph drum, a line which was 
at a distance from the base line proportional to the voltage 
indicated upon the voltm ter, and therefore, to the speed at 
which the car was moving. The exact ordinates for the various 
scale divisions were obtained by direct calibration. In connec- 
tion with the chronograph was a time-marking device, consist- 
ing of a pen operated by an electro-magnet. The current 
which passed through this magnet received an impulse every 
five seconds from the time-marking device used in connection 
with the recording ammeter. In connection with the indica- 

* In subsequent tests it was found more satisfactory to gear the speed 
generator to the car axle by means of sprocket gears and chain. 



84 



ELECTRIC RAILWAY TEST COMMISSION 



tions of the time marker an accurate stop-watch was used for 
the purpose of calibration. 

The Boyer speed recorder consists of a rotary oil pump, the 
speed of which is proportional to that to be measured. This 
pump delivers the oil to a cylinder in which it produces pressure 
upon a piston, the motion of which is recorded upon a strip of 
paper by a pencil mechanism. The oil passes out of the cylin- 
der through a port, the area of which is increased as the piston 
rises, so that a definite position of the piston corresponds to 
each speed. From the cylinder the oil passes back to the 
pump. 

The strip of paper upon which the record is made passes over 
a drum driven from the car axle giving, therefore, a base line 
which is proportional in length to the distance traveled. 

Electrical Measurements. 
The electrical measurements made and the instruments em- 
ployed were as follows: 



Quantity 
Measured. 



Line Pressure. 
Total Current. 
Total Current. 
Motor Currents. 
Motor Pressures 
Total Energy. 



Motor Temper- 
ature. 



Instrument 
Employed. 



Method of Making Measurements. 



Weston Indicating 
Voltmeter. 

G. E. Recording 
Ammeter. 

Weston Milli-volt- 
meter with shunt. 

Weston Milli-volt- 
meter with shunt. 

Weston Indicating 
Voltmeters. 

Thomson Integrating 
Wattmeter. 

Weston Ammeter 
and Milli-voltmeter. 



Every five seconds. 



Continuous records for certain sections 

of tests. 

Read occasionally to check recording 
ammeter. 

Separate tests to determine the division 
of current between the two motors. 

Separate tests to determine division 
of E.M.F. 

Operated continuously. 



Resistance measured periodically and 
rise in temperature deduced there- 
from. 



(Temperatures were checked by numerous thermometer measurements.) 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 85 

The connections and arrangement of instruments to facilitate 
the measurements were as shown in Fig. 28 and Fig. 29. The 
controller diagram and the connections of the motors for the 
power notches of the controller, are shoT\Ti in Part III on Ac- 



Chronograph 

MOTOR 



4/wwwv ~ o ~ 



-G^ 



-&^ 



Chronograph Drum 




Fig. 27. — Speed Recording Mechanism. 



PilSM BOTTOI 



AMMETER 
MaCtNET 



CHRONOfiRAPH 

Kaonet 



^ 







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Chronometer 

Contact Maker 



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\ 



I 



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J 



\ 



Fig. 28. — Diagram of Connections of Recording Instruments including Bell Signal 
and Time Recording Devices. 

celeration Tests. The connections for the braking notches of 
the controller are shown in Part IV on Braking Tests. 



WORKING UP THE RESULTS. 

The results of the tests have been briefly set forth in the 
synopsis. The arrangement of apparatus, diagrams of connec- 
tions, instruments used, and data taken have been discussed 



86 



ELECTRIC RAILWAY TEST COMMISSION 



above. The method used in working up the results will now 
be considered. 

It was not only important to take certain data simultaneously, 
but it was also necessary that these data be taken at certain 
time intervals, and that the time of the start and stop of the car 
should be accurately known with respect to these time intervals. 
It was only by proceeding in this way that the exact relation 
of all data could be obtained. 

With the stop-watch was obtained the total time of run, 




Fig. 29. — Diagram of Connections of Instruments. (Single-Truck Car.) 



from the instant that the controller was placed at the first 
notch until the car came to a standstill. Stop-watch readings 
were also taken for the period of turning the controller on, 
total time of power on, period of drifting, and period of braking. 

From the current record was obtained not only the actual 
value of the current at every instant at which current was 
being taken, but also the actual instant at which the current 
was applied and the instant at which it was cut off. 

Accurate records, with reference to the five second readings 
of the indicating instruments were made on the ammeter and 
speed records, at the instant the five second bell rang. It is 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 87 

evident that all of these readings may be accurately correlated 
with the records of current and speed. 

In working up the final results, it was often necessary to go 
from one to another of these various sources of information, in 
order to obtain a complete knowledge of the conditions existing 
at any given instant. 

The Time-Speed Curves. 

In working up the time-speed curve for a given run of a test, 
it was necessary to first locate the actual time of start of each 
run. This was done by finding the exact instant of start with 
reference to the five second scores on the recording ammeter 
record for the particular run, and transferring these data to the 
speed curve by means of the five second score mark on the 
latter curve. The second intervals from the start were then 
carefully measured off and ordinates erected. A number of 
speed curves for a particular test were worked up in this manner. 
A table was then compiled showing the speed of each of these 
runs at the various second intervals. From this table the 
average speed of all the selected runs was obtained for each 
second interval from the start. The final speed curve was then 
plotted. 

Since all tests did not have the same time interval, it was 
necessary to obtain the average time of run from start to stop 
for a given test. This was done by taking the average time 
for all rims throughout the day, the time of start and stop 
having been carefully recorded at the time the test was made. 
This average time of rim was used in plotting the time-speed 
curve. Upon working up the time-distance curves (which are 
described below) it was found that the average time-speed curve 
as obtained in this manner, did not in all cases permit of the 
exact distances actually traveled from the start to the point 
at which the controller was placed at the full parallel position, 
and to the point at which the power was turned off. As these 
points were fixed by the schedule in each case, they served as 
a check on the time-speed curves. 



88 ELECTRIC RAILWAY TEST COMMISSION 

Time-Distance Curves. 

Since the distance traveled is the summation of the speed 
and the time at any instant, it is evident that the time distance 
curve may be obtained by summing up or integrating the 
areas under the speed time curves for any given interval from 
the start. The time distance curve was obtained in this manner 
and was transferred to the curve sheet. 

The Current Curves. 

The various current curves of a given run were all integrated 
and the final average value of current obtained, as well as the 
actual time which the current was on. The average time the 
current was on and the average current were obtained for all 
the current curves for the total days run. Twelve or thirteen 
curves were then selected which conformed most nearly to 
average conditions as to the shape of the curve, the total time 
the current was on, and the average current. 

The curves were superimposed upon each other and an 
average curve was obtained. The final curve was reintegrated 
and was formed to correspond in general outline, area, and 
time with average conditions. The final curve was enlarged 
and placed upon the curve sheet. 

The Squared Current Curves. 

The curves of squared curren were> obtained by squaring the 
ordinates of the average current curve and plotting the results. 
The area of this curve was taken and the average squared value 
of the current obtained. Finally, the square root of the mean 
square value of the current was obtained for the entire day's 
conditions. The heating of the motors depends upon the 
virtual or square root of the mean square value of the current. 
This curve is not represented graphically on the charts. 

The Pressure Curves. 

Line pressure readings were taken at the stroke of the five 
second bell in each case. The start was intentionally made at 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 89 

different time intervals with respect to the five second bell on 
the various runs, so that the values of pressure might be ob- 
tained for different points between the five second intervals. 
The five second bell period was located with reference to the 
start in the case of each run of a given test. In this way a 
number of readings would be obtained for each second period 
of the voltage curves, and these were recorded upon a data 
sheet. The average value of the pressure at each of the second 
point intervals was then obtained and this average was placed 
upon the curve sheet. 

The Power Curves. 

The curve of total power was obtained by multiplying to- 
gether simultaneous readings of the instantaneous values of 
pressure and current taken from the average curve. The 
curve obtained from these points was plotted and integrated, 
and the average value of power was thus obtained. 

The Division of Current 

In making the tests, an ammeter was placed in each of the 
motor circuits. It was thus found that the division of current 
between the two motors was practically equal. 

This conclusion was reached by getting the results of a large 
number of observations. Knowing this general relation be- 
tween the motors, it was a simple matter to construct a curve, 
showing the individual current in each case. The various 
notches of the controller are clearly indicated on the current 
curves. Knowing the connections between the motors for each 
position of the controller, it is possible to tell whether the 
motors are in series or in parallel at a given controller notch. 
The individual motor current curves are therefore plotted from 
these data and general information, as shown on the curve 
sheet. For the controller notches in which the motors are in 
series operation, the total current is also the individual motor 
current. For the parallel controller notches, however, the total 
current is double that of the individual motor currents. This 



90 ELECTRIC RAILWAY TEST COMMISSION 

part of the current curve for a single motor is consequently 
obtained by taking half of the total current during this period. 

The Division of Pressure. 
The pressure of each of the individual motors was taken at 
certain intervals during the tests. From these data it was 
clearly shown that the motors divided pressure practically 
equally during the period when they were in series. When the 
motors were in parallel, the pressure across each of the motors 
was directly obtained. The method of obtaining the individual 
motor pressure data was the same as that employed in taking 
the line pressure data. That is, these data were taken at the 
sounding of the five second bell in each case, and the five second 
bell interval was not the same for all runs of a given test rela- 
tive to the time of start, so that a mmiber of readings might 
be obtained from the general runs of a given test which would 
show the pressure on the individual motor at the various sec- 
onds, starting from the time at which the current was impressed 
upon the motors. By correlating these data with reference to 
the five second score mark and the time of start of the tests 
in each case, it was possible to obtain a number of data for 
each second from the time of start. By averaging these data, 
a curve showing the pressure of the individual motors in each 
case from one second to the next could be obtained. This 
curve was plotted on the curve sheet. 

The Division of Power, 
Curves showing the division of power between the motors 
and the starting resistances were obtained by multiplying to- 
gether the instantaneous values of pressure and current as 
obtained above for the individual motors and for the starting 
resistance. 

Results of the Tests. 

The numerical results of the various service tests made upon 
the single-truck car are sho\vn in tabular form in the synopsis 
at the beginning of the chapter. It will be noted that the 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 91 

data relating to the test of September 23d are not as complete 
as are those for the other tests. This test was the first of the 
series, and must be considered more or less as a preliminary 
run. 

The results of tests Nos. 2, 3, 4, and 5 are shown in graphical 
form on the following pages of the chapter. These graphical 
representations have been divided into three parts for each test. 
One shows the general results of the test, while the other two 
show some of the more detailed results. 

THE GENERAL DATA. 

The plates showing the graphical representation of the general 
data are plotted on a time base, and curves have been drawn, 
showing the speed, distance traveled, pressure, total current, 
and power at each instant from the start to the stop. These 
diagrams are accompanied in each case by a general log, which 
gives all detailed information concerning the conditions existing 
at the time the test was made and also the general numerical 
results of the test. 

THE DETAILED DATA. 

In addition to the general diagrams there will be found two 
detailed diagrams for each of the tests Nos. 2, 3, 4, and 5, in 
which are shown the division of current, pressure, and power 
between motors and resistance. The first of these diagrams in 
each case shows the division of current and power between the 
two motors and the starting resistances. The second diagram 
in each case shows the total power, power taken by the motors, 
and that lost in the starting resistance. The detailed diagrams 
follow immediately after the general diagrams for a given test. 

TEMPERATURE MEASUREMENTS. 

The final average temperature rise of the motors at the end 
of each test has been recorded in the synopsis and also in the 
general data accompanying the graphical representation of re- 
sults in each case. Temperature measurements were made at 



92 ELECTRIC RAILWAY TEST COMMISSION 

intervals throughout the day in each case. These readings 
were taken both by means of thermometers and by means of 
resistance measurements of armatures and fields. The various 
temperature measurements are shown in the tables at the end 
of the chapter. 

GENERAL LOG SHEET OF TEST NO. 2. 

(Magnetic brake employed in this test.) 

(Illustrated by Figs. 30, 31, and 32.) 

Date, Saturday, September 24, 1904. Place, test tracks north 
of Transportation Building, World's Fair, St. Louis. Weather, 
unsettled, dry first part of day's run, rain at 11.50 a.m. Con- 
dition of track, dry at first, but wet during the latter part of 
run. Average line pressure, 520 volts. 

Distance Measurements. — Length of a single run, 792 feet or 
0.15 of a mile. Stops per mile, 6.7. Distance traveled, from 
start to the point where the controller was at the full parallel 
position, 123 feet. Distance traveled from start to the point 
where the power was shut off, 472 feet. Distance traveled to 
the point where the brakes were first applied, 641 feet. 

Time Measurements. — Time of run (start to stop), 37 
seconds. Time of stop, 15.5 second]. Time of run (start to 
stop), 52.5 seconds. Average time of run for day (including 
stops for temperature readings), 61.6 seconds. Total time of 
day's run, 5.7 hours. Time in turning controller to full parallel 
position, 8.7 seconds. Time during which power was supplied 
for each run, 21 seconds. Time from start to the point of 
'applying brakes, 27 seconds. Time from point of application 
of brakes to stop, 10 seconds. 

Speed Measurements. — Average speed (start to stop), 14.6 
miles per hour. Maximum speed during run, 20.7 miles per 
hour. Schedule speed (start to start), 10.3 miles per hour. 

Acceleration Measurements. — Average acceleration from the 
start to the point where the power was cut off, 0.98 miles per 
hour per second. Maximum acceleration, 2.19 miles per hour 
per second. 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 93 



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Fig. 31. —Division of Current and Pressure, Test No. 2, Sept. 24, 1904. 




Seconds 2 i C 8 10 32 14 16 18 20 

Fig. 32. —Division of Power, Test No. 2, Sept. 24, 1904, 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 95 

Deceleration Measurements. — Average deceleration from the 
point where the brakes were first applied to the end of the run, 
1.8 miles per hour per second. Maximum deceleration, 2.28 
miles per hour per second. 

Current Measurements. — Average current (during time power 
was on), 115.5 amperes. Maximum current during run, 198 
amperes. Sijuareroot of mean square current, 121.5 amperes. 
Form factor (square root of mean square current, divided by- 
average current), 1.05. Average braking current (during 
braking period), 50.6 amperes. Maximum braking current, 90 
amperes. Square root of mean square braking current, 60.3 
amperes. Form factor of braking current, 1.19. 

Power Measurements. — Average power (during time power 
was on), 60,600 watts. Maximum power, 102,000 watts. Aver- 
age power per run (start to stop), 34,000 watts. Average power 
per run (start to start), 24,000 watts. Average power for day 
(including stops for temperature readings), 20,455 watts. 

Energy Measurements. — Average energy per run, 350 watt- 
hours. Average energy per car mile, 2.35 kilowatt hours. Aver- 
age energy per ton mile, 164 watt-hours. Average energy per 
run (obtained from the readings of the integrating wattmeter), 
watt-hours. 

GENERAL LOG SHEET OF TEST NO. 3. 
(Magnetic brake used in this test.) 

(Illustrated by Figs. 33, 34, and 35.) 
Date, Monday, September 26, 1904. Place, test track north 
of Transportation Building, World's Fair, St. Louis. Weather, 
clear, no rain. Condition of track, dry and clean. Average 
line pressure, 511.2 volts. 

Distance Measurements. — Length of a single run, 792 feet, or 
0.15 of a mile. Stops per mile, 6.7. Distance traveled from 
start to the point where the controller was at the full parallel 
position, 123 feet. Distance traveled from start to the point 
where the power was shut off, 472 feet. Distance traveled to 
the point where the brakes were first applied, 641 feet. 



96 



ELECTRIC RAILWAY TEST COMMISSION 



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Fig. 35.— Division of Power in Test No. 3, Sept. 26, 1904. 



98 ELECTRIC RAILWAY TEST COMMISSION 

Time Measurements. — Time cf run (start to stop), 36.8 sec- 
onds. Time of stop, 14.9 seconds. Time of run (start to start), 
51.7 seconds. Average time of run for day (including stops for 
temperature readings), 62.3 seconds. Total time of day's run, 
7.6 hours. Time in turning controller to full parallel position, 
8.5 seconds. Time during which power was supplied for each 
run, 20.8 seconds. Time from start to point of applying 
brakes, 25 seconds. Time from point of application of brakes 
to stop, 11.8 seconds. 

Speed Measurements. — Average speed (start to stop), 14.7 
miles per hour. Maximum speed during run, 20.6 miles per 
hour. Schedule speed (start to start), 10.5 miles per hour. 

Acceleration Measurements. — Average acceleration from the 
start to the point where the power was cut off, 0.99 miles per 
hour per second. Maximum acceleration, 2.5 miles per hour 
per second. 

Deceleration Measurements. — Average deceleration from the 
point where the brakes were first appUed to the end of run, 1.51 
miles per hour per second. Maximum deceleration, 1.95 miles 
per hour per second. 

Current Measurements. — Average current (during time power 
was on), 116 amperes. Maximum current during run, 199 
amperes. Square root of mean square current, 122 amperes. 
Form factor (square root of mean square current divided by 
average current), 1.05. Average braking current (during brak- 
ing period), 58 amperes. Maximum braking current, 112 am- 
peres. Square root of mean square braking current, 71.3 
amperes. Form factor of braking current, 1.23. 

Power Measurements. — Average power (during time power 
was on), 59,299 watts. Maximum power, 101,000 watts. 
Average power per run (start to stop), 33,600 watts. Average 
power per run (start to start), 23,884 watts. Average power 
for day (including stops for temperature readings), 19,820 watts. 

Energy Measurements. — i\.verage energy per run, 343 watt- 
hours. Average energy per car mile, 2.3 kilowatt hours. 
Average energy per ton mile, 161 watt-hours. 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 99 

GENERAL LOG SHEET OF TEST NO. 4. 
(Hand brake employed in tliis test.) 

(Illustrated by Figs. 36, 37, and 38.) 

Date, Thursday, October 6, 1904. Place, test tracks north 
of Transportation Building, World's Fair, St. Louis. Weather, 
clear, no rain. Condition of track, dry and clean. Average line 
pressure, 514 volts. 

Distance Measurements. — Length of a single run, 789 feet or 
0.15 of a mile. Stops per mile, 6.7. Distance traveled from 
start to the point where the controller was at full parallel posi- 
tion, 100 feet. Distance travelled from start to the point 
where the power was shut off, 390 feet. Distance travelled 
to the point where the brakes were first applied, 612 feet. 

Time Measuretnents. — Time of run (start to stop), 39 
seconds. Time of stop, 11 seconds. Time of run (start to 
start), 50 seconds. Average time of run for day (including 
stops for temperature readings), 64.1 seconds. Total time of 
days's rmi, 6.8 hours. Time in turning controller to full parallel 
position, 8.7 seconds. Time during which power was supplied 
for each run, 19.5 seconds. Time from start to the point of 
applying brakes, 22.5 seconds. Time from point of apphcation 
of brakes to stop, 16.5 seconds. 

Speed Measurements. — Average speed (start to stop), 13.8 
miles per hour. Maximum speed during run, 20.8 miles per 
hour. Schedule speed (start to start), 10.8 miles per hour. 

Acceleration Measurements. — Average acceleration from start 
to the point where the power was cut off, 1.07 miles per hour 
per second. Maximum acceleration, 2.14 miles per hour per 
second. 

Deceleration Measurements. — Average deceleration from the 
point where the brakes were first applied to the end of run, 
1.21 miles per hour per second. Maximum deceleration, 4.3 
miles per hour per second. i nr /* 



100 



ELECTRIC RAILWAY TEST COMMISSION 



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SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 101 



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Fig. 38. —Division of Power in Test No. 4, Oct. 6, 1904, 



102 ELECTRIC RAILWAY TEST COMMISSION 

Current Measurements. — Average current (during time power 
was on), 121 amperes. Maximum current during run, 204 
amperes. Square root of mean square current, 124 amperes. 
Form factor (square root of mean square current divided by 
average current), 1.03. 

Power Measurements. — Average power (during time power 
was on), 62,194 watts. Maximum power, 105,000 watts. Aver- 
age power per run (start to stop), 31,200 watts. Average 
power per run (start to start), 24,336 watts. Average power 
for day (including stops for temperature readings), 19,000 
watts. 

Energy Measurements. — Average energy per run, 338 watt- 
hours. Average energy per car mile, 227 watt-hours. Average 
energy per ton mile 159 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 5. 
(Magnetic brake employed in this test.) 

(Illustrated by Figs. 39, 40, and 41.) 

Date, Friday, October 7, 1904. Place, test track north of 
Transportation Building, World's Fair, St. Louis. Weather, 
clear, no rain. Condition of track, dry and clean. Average line 
pressure, 527.2 volts. 

Distance Measurements. — Length of a single run, 789 feet, or 
0.15 of a mile. Stops per mile, 6.7. Distance traveled from 
start to the point where the controller was at the full parallel 
position, 100 feet. Distance travelled from start to the point 
where the power was shut off, 390 feet. Distance travelled to 
the point where the brakes were first applied, 612 feet. Time 
of run (start to stop), 37 seconds. Time of stop, 13 seconds. 
Time of run (start to start), 50 seconds. Average time of run 
for day (including stops for temperature readings), 66.6 seconds. 
Total time of day's run, 6.8 hours. Time of turning controller 
to full parallel position, 9 seconds. Time during which power 
was supphed for each run, 19.5 seconds. Time from start to 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 103 

the point of applying brakes, 25.3 seconds. Time from point 
of application of brakes to stop, 11.7 seconds. 

Speed Measurements. — Average speed (start to stop), 14.5 
miles per hour. Maximum speed during run, 20.9 miles per 
hour. Schedule speed (start to start), 10.8 miles per hour. 

Acceleration Measurements. — Average acceleration from the 
start to the point where the power was cut off, 1.07 miles per 
hour per second. Maximum acceleration, 1.66 miles per hour 
per second. 

Deceleration Measurements. — Average deceleration from the 
point where the brakes were first applied to the end of run, 
1.71 miles per hour per second. Maximum deceleration, 3.0 
miles per hour per second. 

Current Measurements. — Average current (during time power 
was on), 116 amperes. Maximum current during run, 200 
amperes. Square root of mean square current, 123.2 amperes. 
Form factor (square root of mean square current divided by 
average current), 1.05. Average braking current (during brak- 
ing period), 50.5 amperes. Maximum braking current, 130 
amperes. Square root of mean square braking current, 692 
amperes. Form factor of braking current, 1.36. 

Power Measurements. — Average power (during time power 
was on), 61,577 watts. Maximum power, 103,400 watts. 
Average power per run (start to stop), 32,500 watts. Energy 
per run (start to start), 24,100 watts. Average power for day 
(including stops for temperature readings), 18,054 watts. 

Energy Measurements. — Average energy per run, 334 watt- 
hours. Average energy per car mile, 2.24 kilowatt hours. 
Average energy per ton mile, 157 watt-hours. 



104 



ELECTRIC RAILWAY TEST COMMISSION 



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Fitf, 41. —Division of Power in Test No. 5, Oct. 7. 1904. 



106 ELECTRIC RAILWAY TEST COMMISSION 

Discussion of Results. 

The service tests on the single-truck city car give data which 
may be studied in two different ways. In the first place, they 
afford information as to the performance of a car under a sched- 
ule which is frequently met with in service in large cities, the 
car tested being of ample size and power capacity for such ser- 
vice. In the second place, the data allow of a comparative 
study of the action of hand and power brakes upon the same 
car. In this particular case, the power brake used was of the 
magnetic type, but, aside from the effect that this system pro- 
duces upon the motors, substantially the same results are secured 
with any other power brake. 

Taking up a consideration of the comparative speed perform- 
ance in the several tests, it is noted that in all of the tests with 
the power brake the ratio of the maximum to the average speed 
is much lower than in the tests with the hand brake, the differ- 
ence amounting to about 7 per cent. This shows that with 
the power brake and with the same maximum speed, it is pos- 
sible to secure a greater average speed. Moreover, this increase 
of average speed is secured without additional expenditure of 
power, as it results from the additional time during which 
the car may be allowed to drift after the shutting off of the 
power and before the application of the brakes. The efficiency 
of each run is therefore greater with the power brakes than 
with the hand brakes. In these tests the rates of acceleration 
were as nearly uniform as possible, and no significance is to be 
attached to the. slight variations in the maximum and average 
accelerations. 

The variations in acceleration which are noted are due to the 
employment of a slightly different schedule of operation in Tests 
Nos. 4 and 5 from that of Tests Nos. 2 and 3. It will be remem- 
bered that Tests Nos. 4 and 5 were made some time after the 
others, and during the interval between considerable study had 
been put upon improving the schedule, with the result that Tests 
Nos. 4 and 5 may be considered as somewhat superior to the 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 107 

others. In the later tests, also, the operators had become more 
skilled in the manipulation of the apparatus, and they were thus 
able to secure more uniform results. This is illustrated by the fact 
that they were able to produce in Tests Nos. 4 and 5, substantially 
the same maximum speed and schedule speed, with the average 
rates of acceleration on the two days almost exactly alike. The 
maximum accelerations differed somewhat, but it was found 
very difficult to obtain exactly equal maximum rates of accel- 
eration, and this matter affects the results to a negligible extent. 
The speed recording devices did not possess such a degree of sen- 
sitiveness that much reliance can be placed upon the measure- 
ments of maximum acceleration, and as the maximum currents 
were in all cases substantially the same, it is evident that the 
values of maximum acceleration were closer together than the 
figures indicate. 

The measurements of average deceleration show in marked 
manner the increase in braking ability of the car equipped with 
the power brakes. The average time from the point of the ap- 
plication of brakes in the case of the power brake is slightly over 
eleven seconds, while with the hand brakes this value is above 
sixteen seconds. 

No attempt was made in the service tests to operate the 
power brakes at abnormal rates, but a smooth, easy stop was 
made in each case. The increase in the braking rate due to 
the use of the power brake was from 30 to 40 per cent, and 
the form of the braking curve was much better. A peculiar 
fact is noted in regard to the maximum deceleration in Test No. 
4. It will be noted that this was over four miles per hour per 
second, and very much higher than any of the results with the 
power brakes. This great deceleration occurs just at the in- 
stant of stop and it is due to the increase in friction between 
brake shoes and car wheels as the car approaches rest. Natur- 
ally, the motorman tightens his brake as far as his strength will 
allow toward the end of the braking period, thereby increasing 
the pressure of the brake shoes more or less gradually as the de- 
celeration progresses. In addition to this^ the increase in the 



108 ELECTRIC RAILWAY TEST COMMISSION 

coefficient of friction between shoes and wheel with the diminish- 
ing relative velocity between them, results in the final seizure of 
the wheels by the shoes, and the car is brought to an abrupt stop. 
It is thus noted that with the hand brake the maximum decelera- 
tion is over three times the average, while in the case of the 
power brakes it is never as much as twice the average. In this 
particular form of power brake, the braking force automati- 
cally decreases as the speed lowers, and thus a more uniform 
speed is produced, the pressure on the brake shoes being lowest 
when the coefficient of friction is greatest. The tests show a 
more uniform deceleration with the power brake than with the 
hand brake. 

In all of the tests the energy consumption is practically the 
same, the difference being due to minor causes so that there is 
no material saving in this item obtained by the use of the power 
brakes. It is interesting to note that in each successive test the 
number of kw. hours per car-mile was slightly reduced. As this 
decrease is very regular, it is probably due to the more skilful 
operation of the car by which the pre-determined cycle of opera- 
tions was more accurately adhered to. This decrease amounts 
to not over 5 per cent during the series of tests. There is no 
significance in the fact that with the hand brake a slightly 
greater current was used than in the other tests, as the varia- 
tion is not sufficient to allow any conclusions to be drawn. 
Both the average and maximum currents are quite uniform 
throughout the tests and show very careful handling on the part 
of the motorman, who operated the controller under the direc- 
tion of an observer provided with an accurate stop watch. It 
will be noted that the form factor, or ratio of the square root 
of the mean square current to the average current, is re- 
markably uniform, being substantially the same throughout the 
tests, that is 105 per cent. This shows that the cycle of opera- 
tions, as far as the electrical part was concerned, was reason- 
ably imiform. 

A most important feature of this test was the determination 
of the effect of the current supplied to the brakes by the motors, 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 109 

upon the heating of the motors. This extra duty upon the 
motors interferes with the natural cooUng which would other- 
wise occur at times when the power is shut off. Heating of the 
motors by the braking current is due to two causes, the core 
losses and the armature and field copper losses. The details of 
this matter will be found in Chapter X, in which the tests on 
this brake are especially discussed. For the present purpose 
it is sufficient to note that a certain current was supplied in 
each case to the brakes by the motors. The current averaged 
a httle less than 55 amperes in Tests Nos. 2, 3, and 5, and 
the time during which this current flowed was somewhat over 
eleven seconds. The form factor of this current is high on 
accoimt of the peculiar peaked form of the current curve. An 
average value of the form factor is 128 per cent. The average 
comparative heating effect of the braking current and the power 
current can therefore be readily determined in the two cases 
from the values of the products of the squares of the current 
and the corresponding intervals of time in seconds. The aver- 
ages of these products for Tests Nos. 2, S, and 5 are 751 for the 
braking period, and 2497 for the power period. 

While the core losses have some effect in heating the motors, 
this effect is not large compared with the heating due to the cur- 
rent in this case, partly because the average e.m.f. during the 
braking period is low and because the core loss is not a large per- 
centage of the total heating in any case. Attention should be 
called to the fact that the shunt around the motor field de- 
flected a considerable part of the current from this circuit and 
reduced the field heating to a corresponding extent. 

The temperature measurements show that a somewhat 
greater rise of temperature is produced by the additional duty 
imposed upon the motors by the magnetic brake. In ordinary 
work this would necessitate the employment of slightly 
larger motors where the power brakes are used. The difference 
in temperature, however, is not very great, and it corresponds 
to that which would be expected in view of the amount of cur- 
rent supplied to the brakes, and the duration of the same. In 



110 ELECTRIC RAILWAY TEST COMMISSION 

this test the car was eqmp})ed with motors of ample size for 
both the regular and braking service. The car weighed without 
passengers twelve and one-fourth tons, and the motors were rated 
at 50 nominal horse power, giving a power allowance of nearly 
8.2 horse power per ton. The results of this test show that the 
car could have been easily operated on the schedule used with 
a smaller powder equipment, but as the magnetic brake is par- 
ticularly well adaped to a hilly road where a large motor equip- 
ment is necessary, it was appropriate that motors of ample 
capacity should be placed on the car. It can be stated, there- 
fore, that the car was well adapted for operation in accordance 
with the schedule used without undue heating of the motors. 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 111 



Motor Temperature Data. 

Table II. — Air and Motor Temperature in Degrees Centigrade Single- 
Truck Car, Test No. 1, Sept. 23, 1904. 







Time. 






8.30 A.M. 


11.20 A.M. 


2.15 P.M. 


5.40 P.M. 


Hours from the Start 


0.0 


2.8 


5.7 


9.2 



Temperature Readings by Thermometer. 



Outside Air 

Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2. 




26.5 
66.0 
64.0 
47.0 
47.5 
70.0 
75.0 
66.0 
74.0 



Temperature Rise Above the Air Temperature. 



Field, Motor No. 1 


0.0 


16.5 


38.5 


39.5 


Field Motor No 2 


-0.5 
-0.5 


13.5 

8.0 


29.0 
13.0 


37.5 


Frame, Motor No. 1 


20.5 


Frame, Motor No. 2 


-0.5 


7.0 


16.0 


21.0 


Air Gap, Motor No. 1 


1-0 


22.5 


36.5 


43.5 


Air Gap, Motor No. 2 ...... . 


0.5 


20.0 


36.0 


48.5 


Commutator, Motor No. 1 . . . 


1.0 


36.5 


38 »0 


39 .,5 


Commutator, Motor No. 2 . . . 


1.0 


29.5 


45.0 


47.5 



Temperature Rise Above an Air Temperature of 25° Centigrade. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 . 
Commutator, Motor No 2. 




39.2 
37.2 
20.4 
20.8 
43.2 
48.2 
39.2 
47.2 



112 



ELECTRIC RAILWAY TEST COMMISSION 



Table III. — Air and Motor Temperature in Degrees Centigrade Single-Truck 
Car, Test No. 2, September 24, 1904. 





Time. 




9.45 A.M. 


1.25 P.M. 


3.50 P.M. 


Hours from the Start 


0.0 


3.7 


6 1 







I 



Temperature Readings by Thermometer. 



Outside Air 

Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 




22.2 
52.0 
57.0 
39.5 
42.0 
64.0 
68.0 
63.5 
68.0 



Temperature Rise Above the Air Temperature. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 




29.8 
34.8 
17.3 

19.8 
41.8 
45.8 
41.3 

45.8 



Temperature Rise Above an Air Temperature op 25° Centigrade. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 




30.2 
35.3 
17.6 
20.1 
42.4 
46.5 
41.9 
46.5 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 113 



Table IV. — Air and Motor Temperature in Degrees Centigrade Single- 
Truck Car, Test No. 3, September 26, 1904. 





Time. 




8.30 

A.M. 


11.00 

A.M. 


12.35 

P.M. 


4.10 

P.M. 


5.30 

P.M. 


Hours from the Start 


0.0 


2.5 


4.1 


7.7 


9.0 



Temperature Readings by Thermometer. 



Outside Air 

Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



25.0 


29.0 


30.7 


33.7 


24.0 


36.0 


48.0 


64.5 


24.0 


38.0 


52.0 


69.0 


24.0 


31.0 


37.0 


49.2 


24.0 


31.0 


38.5 


51.0 


23.5 


44.0 


57.2 


73.0 


23.5 




58.0 


78.0 


24.0 


52.6 


59.8 


75.5 


24.0 


57.0 


68.0 


83.2 



32.8 
65.5 
70.0 
50.0 
52.0 
71.5 
77.5 
76.0 
78.0 



Temperature Rise Above the Air Temperature. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



—1.0 


7.0 


17.3 


30.8 


-1.0 


9.0 


21.3 


85.3 


-1.0 


2.0 


6.3 


15.5 


-1.0 


2.0 


7.8 


17.3 


-1.5 


15.0 


26.5 


39.3 


-1.5 




27.3 


44.3 


-1.0 


23.6 


29.1 


41.8 


-1.0 


28.0 


37.3 


49.5 



32.7 
37.2 
17.2 
19.2 
38.7 
44.7 
43.2 
45.2 



Temperature Rise Above on Air Temperature of 25° Centigrade. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



-1.0 


6.9 


16.8 


29.3 


-1.0 


8.8 


20.7 


33.6 


-1.0 


2.0 


6.1 


14.8 


-1.0 


2.0 


7.6 


16.5 


-1.5 


14.7 


25.7 


37.6 


-1.5 




26.5 


42.2 


-1.0 


22.6 


28.2 


39.8 


-1.0 


27.4 


36.2 


47.1 



31.4 
35.7 
16.5 
18.5 
37.2 
42.9 
41.5 
43.4 



114 



ELECTRIC RAILWAY TEST COMMISSION 



Table V. — Air and Motor Temperature in Degrees Centigrade Single-Truck 
Car, Test No. 4, October 6, 1904. 









Time. 








10.10 

A.M. 


1.10 

P.M. 


2.30 

P.M. 


• 4.15 

P.M. 


5.40 

P.M. 


Hours from the Start 


0.0 


3.0 


4.3 


6.1 


7.5 



Temperature Readings by Thermometer. 



Outside Air 

Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



14.0 


18.5 


19.6 


17.0 


14.0 


38.0 


42.0 


39.0 


14.0 


34.0 


50.0 


43.0 


13.5 


26.0 


28.8 


32.5 


14.0 


21.2 


27.0 


31.5 


15.0 


42.0 


47.1 


54.0 


15.0 


44.0 


53.5 


51.5 


15.0 


47.0 


52.0 


53.2 


15.0 


50.0 


58.0 


60.0 



17.3 

50.0 
51.0 
32.5 
30.0 
56.5 
59.0 
58.5 
57.0 



Temperature Rise Above the Air Temperature. 



Field, Motor No. 1 

Field, Motor No. 2 

I'rame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



0.0 


19.5 


22.4 


22.0 


0.0 


15.5 


30.4 


26.0 


-0.5 


7.5 


9.2 


15.5 


0.0 


2.7 


7.4 


14.5 


1.0 


23.5 


27.5 


37.0 


1.0 


25.5 


33.9 


34.5 


1.0 


28.5 


32.4 


36.2 


1.0 


31.5 


38.4 


43.0 



32.7 
33.7 
15.2 
12.7 
39.2 
41.7 
41.2 
39.7 



Temperature Rise Above an Air Temperature of 25° Centigrade. 



Field, Motor No. 1 

Field, Motor No. 2 

Frame, Motor No. 1 

Frame, Motor No. 2 

Air Gap, Motor No. 1 

Air Gap, Motor No. 2 

Commutator, Motor No. 1 
Commutator, Motor No. 2 



0.0 


20.1 


23.0 


22.9 


0.0 


16.0 


31.2 


27.0 


-0.5 


7.8 


9.5 


16.1 


0.0 


2.8 


7.6 


15.1 


1.1 


24.3 


28.2 


38.5 


1.1 


26.4 


34.8 


35.9 


1.1 


29.4 


33.2 


37.6 


1.1 


32.5 


39.4 


44.7 



34.0 
35.0 
15.8 
13.2 
40.7 
43.3 
42.7 
41.2 



SERVICE TESTS OF A SINGLE-TRUCK CITY CAR 1X5 

Table VI. — Air and Motor Temperature in Degrees Centigrade Single-Truck 
Car, Test No. 5, Oct. 7, 1904. 





Time. 




8.45 

A.M. 


9.20 

A.M. 


11.35 

A.M. 


1.05 

P.M. 


2.35 

P.M. 


4.10 

P.M. 


Hours from the Start .... 


0.0 


0.6 


2.8 


4.3 


5.8 


7.4 



Temperature Readings by Thermometer. 



Outside Air 

Field, Motor No. 1 

Field, Motor Xo. 2 

Frame, Motor Xo. 1 

Frame, ^lotor Xo. 2 

Air Gap, Motor Xo. 1 . . . . 
Air Gap, Motor Xo. 2. . . . 
Commutator, Motor Xo. 1 
Commutator, Motor Xo. 2 



12.0 


17.0 


19.5 


22.5 


22.1 


14.0 


24.0 


35.0 


42.0 


50.0 


14.0 


25.5 


39.5 


45.0 


47.0 


13.5 


18.0 


32.0 


29.0 


33.5 


11.7 


18.1 


24.8 


31.7 


36.0 


15.2 


29.0 


36.5 


46.0 


55.5 


16.0 


28.7 


38.5 


51.0 


59.5 


15.0 


39.5 


47.0 


58.0 


63.0 


15.0 


38.7 


52.0 


58.7 


64.5 



21.8 
51.0 
54.0 
37.5 
37.0 
59.0 
64.8 
64.0 
68.0 



Temperature Rise Abo^^e the Air Temperature. 



Field, Motor Xo. 1 

Field, Motor Xo. 2 

Frame, Motor Xo. 1 

Frame, Motor Xo. 2 

Air Gap, Motor Xo. 1 . . . . 

Air Gap, Motor Xo. 2 

Commutator, Motor Xo. 1 
Commutator, Motor Xo. 2 



2.0 


7.0 


15.5 


19.5 


27.9 


2.0 


8.5 


20.0 


22.5 


24.9 


1.5 


1.0 


12.5 


6.5 


11.4 


-0.3 


1.1 


• 5.3 


9.2 


13.9 


3.2 


12.0 


17.0 


23.5 


33.4 


4.0 


11.7 


19.0 


28.5 


37.4 


3.0 


22.5 


27.5 


35.5 


40.9 


3.0 


21.7 


32.5 


36.2 


42.4 



29.2 
32.2 
15.7 
15.2 
37.2 
43.0 
42.2 
46.2 



Temperature Rise Above an Air Temperature of 25° Centigrade. 



Field, Motor Xo. 1 

Field, Motor Xo. 2 

Frame, Motor Xo. 1 

Frame, Motor Xo. 2 

Air Gap, Motor Xo. 1 . . . . 
Air Gap, Motor Xo. 2. . . . 
Commutator, Motor Xo. 1 
Commutator, Motor Xo. 2 



2.1 


7.3 


15.9 


19.7 


28.3 


2.1 


8.8 


20.6 


22.8 


25.3 


1.6 


1.0 


12.8 


6.6 


11.6 


-0.3 


1.1 


5.4 


9.3 


14.1 


3.4 


12.5 


17.5 


23.8 


33.9 


4.3 


12.2 


19.5 


28.9 


38.0 


3.2 


23.4 


28 . 3 


36.0 


41.6 


3.2 


22.6 


33.4 


36.7 


43.0 



29.6 
32.7 
15.9 
15.4 
37.8 
43.7 
42.9 
47.0 



CHAPTER III. 
SERVICE TESTS ON A DOUBLE-TRUCK CITY CAR. 



Objects of the Tests. 

The principal object of these tests was to study the general 
performance of a typical double-truck city car when operated 
under normal conditions of service in a large city. The car was 
tested both when the weather was clear and the track dry, and 
when the weather was bad and the track wet. Consequently, 
comparative data was obtained of the perforraance of the car 
when operated under different weather conditions. 

Synopsis of Results 

Table VII. — Synopsis of Results. Service Test on Double-Truck City Car. 



Weather Conditions 

Total Duration of Test (Hours) 

Length of Round Trip (Miles) 

Interval of Round Trip Start to Stop (Minutes) 

No. of Passengers per round trip (Total) 

No. of Passengers (Ave.) 

Ave. Line Pressure (Volts) 

Ave. Current (Amperes) 

Ave. Power (for Round Trip) Watts 

Ave. Length of Run (Feet) 

Stops per Mile 

Ave. Interval of Stop (Sec.) 

Ave. Interval of Run Start to Stop (Sec.) . . . . 
Ave. Interval of Run Start to Start (Sec.) . . . 

Schedule Speed (Inc. Stops) M.P.H 

Average Speed Actual Running Time M.P.H. 

Ave. Watt-Hours Per Trip 

Ave. kw. Hours per Car-Mile 

Ave. Watt-Hours Per Ton-Mile 

Ave. Watt-Hours Per Passenger (Total) . . . . 
Temp. Rise of Motors Above an Air Tem- 
perature of 25° C.^ 



Test 
No. 6. 



Rainy 

12. 05 

10.53 

66.5 

141 

35 

488.4 

53.3 

26,032 

1,264 

4.1 

8.6 

82.2 

90.8 

9.50 

10.47 

28,852 

2.74 

122 

203 

44.8° C. 



Test 
No. 7. 



Clear 

12.20 

10.53 

67.8 

131 

32 

471.8 

53.3 

25,147 

1,158 

4.5 

8.6 

76.4 

85.0 

9.32 

10.34 

28,416 

2.70 

120 

217 

60° 



Test 
No. 8. 



Clear 

11.45 

10.53 

69.3 

130 

32 

475.6 

53.2 

25,292 

869 

5.9 

5.9 

59.1 

65.0 

9.12 

10.01 

29,212 

2.77 

123 

225 

59° 



Test No. 6, Aug. 18, 1904, Wet Track, Independent Motor-Compressor. 
Test No. 7, Aug. 24, 1904, Dry Track, Independent Motor-Compressor. 
Test No. 8, Aug. 29, 1904, Dry Track, Storage Air System. 

1 Average of all Motor Temperatures at the end of the run. 

116 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 117 
GENERAL CONDITIONS OF THE TESTS. 

The service tests upon the double-truck city car were made 
on the Unes of the St. Louis Transit Company, now the United 
Railways Company of St. Louis. This company is the largest 
transit company in St. Louis, and operates over 350 miles of 
single track on over 175 miles of streets. 

The company placed every facility at the disposal of the 
commission during the tests, and endeavored in every way to 
expedite the work. The tests were not made upon the test 
tracks on the Exposition Grounds for the reason that the city 
cars are not adjusted to the standard gage. The test track was 
also rather short for the size of the car tested, while the condi- 
tions existing on the city lines were excellent for securing data 
showing the performance of a car in regular city service. 

The car selected for test is fully described in Chapter I, It 
was numbered "2600" and was a new car of the most recent 
type employed by the St. Louis Transit Company. 

THE PARK AVENUE LINE. 

The Park. Avenue line was selected for the tests in preference 
to other lines of the Transit Company's systems, because its 
traffic was affected but slightly by the St. Louis Exposition, and 
it consequently conformed more nearly to ordinary conditions 
of service. As this line did not run to the Fair Grounds, the 
excess travel over ordinary conditions was due principally to 
passengers from and to the Union Depot at 18th Street. 

The Park Avenue line is a double-track line running from 
Tower Grove Park to Third Street and Washington Avenue, a 
total distance of 5.26 miles. At the time the tests were made 
an average of 50 cars were in daily service upon this route, with 
a headway of from one to one and one-half minutes. A map of 
the route giving the location of the principal streets, is shown 
m Fig. 42. 

The track gage on the hnes of the Transit Company is 4 ft. 
10 in., instead of the standard gage, 4 ft. 8i in. This track gage 



118 



ELECTRIC RAILWAY TEST COMMISSION 



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Fig. 42. — Map of Park Auenue Line, St Louis, 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 119 

has been used in St. Louis for a number of years, and is required 
by the city authorities. The track is all laid with girder rails, 
a portion being 78 lbs. per yard, another portion 80 lbs. per 
yard, while still a third portion weighs 107 lbs. per yard. The 
height of rail and weight per yard for the various sections of 
track are shown in the following table: 



Location. 


Height of 
Rail in 
Inches. 


Tvpe of 
Rail. 


Weight per 
Yard in 
Pounds. 


From Tower Grove Park to Grand Ave. 

and from Jefferson Ave. to Chouteau 

Ave. 
From Mississippi Ave. to 18th St. on 

Chouteau Ave. 
From Grand Ave. to Jefferson Ave. and 

from ISth St. and Chouteau Ave. to 

3d St. and Washington Ave. 


6 

7 
9 


Girder 

Girder 
Girder 


78 

80 
107 



The track is laid upon white oak ties, standard size, spaced 
two-foot centers. From Third Street to Mississippi and Chou- 
teau Avenues the track is paved with granite. From Missis- 
sippi and Chouteau Avenues to the end of the line, at Tower 
Grove Park, the track is macadamized. In both sections the 
track pavement corresponds to the street pavement. 

From the Third Street loop to Grand Avenue the rails are 
double bonded with No. 0000 B and S gage wire, riveted to the 
rail. No cross bonding occurs in this section. From Grand 
Avenue to Tower Grove Park the line has cast- welded joints. 
Where these joints have been found to be defective they have 
been bonded with copper bonds similar to those in the section 
from Third Street to Grand Avenue. 

The line construction is of the span wire type with poles built 
up of iron tubing. The average distance between spans is 105 
ft. The trolley wire is of No. 00 B and S gage, and is round 
in section. The feeder system is sho^vn in Fig. 42. The number 
of feeders and the points where the feeders tap into the trolley 
wire are shown on this diagram. 



120 



ELECTRIC RAILWAY TEST COMMISSION 



The power was furnished from the central power station. 
During the morning and evening peaks of the load, the Union 
Depot station was connected in parallel with the central station 
feeders supplying the 18th Street Bridge section, and during the 
evening peak the Washington Avenue station was connected 



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100 60 



90 46 



80 40 



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Fig. 43.— Curves Showing the General Performance of General Electric Co. 

No. 54 motor. 

in parallel with the feeders from the central station supplying 
the Washington Avenue section. 

Motive Power Equipment. 

The motive power equipment of this car has already been 
described in a general way in Chapter I. As the service capac- 
ity of the motors has an important bearing upon the tests 
described in the present chapter, their characteristics in opera- 
tion are here briefly discussed. 

The performance of these motors with a gear ratio of 14 to 67 
is shown in Fig. 43. The curves are drawn from data furnished 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 121 




122 ELECTRIC RAILWAY TEST COMMISSION 

by the manufacturer, and show the speed, tractive effort, and 
brake horse power which the motors develop when taking from 
10 to 80 amperes, and with a pressure of 500 volts at their ter- 
minals. The curves also show the total electrical power input 
and efficiency of the motors under the same loads. 

The manufacturers give the rating of these motors at 25 horse 
power with 45 amperes input and 500 volts at the motor termi- 
nals. This output is based upon the standard rating of the 
American Institute of Electrical Engineers. Its rules state 
that the commercial rating of a railway motor shall be the horse- 
power output developed in a stand test producing 75° C. rise of 
temperature above an air temperature of 25° C, after one hour's 
continuous run at 500 volts terminal pressure, with the motor 
covers removed. 

General Description of the Tests. 

Service tests were made on this car on August 18th, August 
24th, and August 29th, 1904. While the car was operated on 
the same schedule and over the same line in all three service 
tests, the conditions were somewhat different in each. 

Test No. 6. — Upon Avigust 18th the car was operated with 
the individual motor-compressor system of air braking. The day 
proved to be rainy with an accompanying wet track and muddy 
street. Consecj^uently, it was deemed advisable to make an- 
other series of runs upon a day when the weather conditions 
would permit of a more representative test from the standpoint 
of average operating conditions. 

Test No. 7. — The service tests of August 24tli were made 
under conditions of a clear day and a dry track. A comparison 
of the results of this test with test No. 6 shows m^any interest- 
ing features relating to the service conditions under differing 
weather conditions. 

Test No. 8. — On August 29th the storage system of air .brak- 
ing was used. The day was clear, and the track dry. From the 
standpoint of service tests. Test No. 8 is similar to Test No. 6. 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 123 

In making the car tests upon August 18th, 24th, and 29th, the 
object was not only to investigate service conditions, but also to 
study braking conditions. Braking tests under similar condi- 
tions, using an individual motor-compressor, were obtained 
both on a dry track on a clear day, and on a wet track on a rainy 
day, the data being recorded as a part of the general tests of 
August 18th and 24th. By the tests of August 24th and 29th 
a comparison is also afforded of air braking where an individual 
motor-compressor system is employed as against the storage 
system of air braking. 

Part IV of this report contains the results and deductions re- 
lating to the braking data obtained in these and other tests upon 
the braking of electric cars. 

Tests Nos. 6, 7, and 8 were made while the car was running in 
ordinary service, four of the seats being given up to the accomo- 
dation of the test corps and the necessary instruments. 

The schedule of the car under test was as follows : 

Running Schedule of Car 2600 in the Service Tests conducted on 
the Park Avenue Line, August ISth, 2Ath, and 29th, 1904. 



Tower Grove Loop. 


Park and Vandeventer. 


Third and Washington. 




6.31 A.M. 


7.00 A.M. 


7.38 A.M. 


7.42 


8.14 


8.50 


8.56 


9.24 


10.02 


10.06 


10.36 


11.09 


11.15 


11.42 


12.15 P.M. 


12.21 P.M. 


12.48 P.M. 


1.21 


1.27 


1.54 


2.27 


2.33 


3.00 


3.33 


3.39 


4.06 


4.44 


4.50 


5.18 


5.56 


6-02 


6.30 



ORIGINAL MEASUREMENTS. 



For the purpose of making the measurements necessary for 
determining the car performance, the electrical input, and the 
motor heating, the following groups of measurements were made : 



124 



ELECTRIC RAILWAY TEST COMMISSION 



Electrical Measurements. 

These included readings of line pressure at five-second inter- 
vals throughout the test and the car current as recorded, by a 
general electric recording ammeter. 

The following table gives in compact form the details of the 
electrical measurements : 



Quantity Measured. 


Instruments Employed. 


Method of Making Mea- 
surements. 


Line Pressure 


Weston Indicating 
Voltmeter. 

G. E. Recording Am- 
meter. 

Weston Milli-voltmeter 
with shunt. 

Weston Ammeter and 
Milli-voltmeter. 


Readings taken every 5 

seconds. 
Continuous record for 


Total Current 


Total Current 


entire tests. 

Read occasionally to 
check recording am- 
meter. 

Resistance measured pe- 
riodically and rise in 
temperature deduced 
therefrom. 


Motor Armature resist- 
ances. 



Speed and Distance Records. 

These included a graphical speed record on the Boyer re- 
corder ; frequent and regular readings of speed by means of a 
magneto-generator driven by the car axle; readings of the time 
and duration of each stop, of the time and duration of each 
run, and of the time of passing the farther crossings of the 
street intersections. 

Temperature Measurements. 

These included the determination of the electrical resistance 
of the motor armatures at reasonably frequent intervals; and 
readings of the air temperature. Thermometer readings of motor 
temperatures were also taken. 

Sundry Measurements. 

Other data recorded cover the number of passengers carried 
at any time, and the weather and track conditions. 

In addition to these measurements all quantities relating to 
the braking equipment were carefully measured, and the results 
of this work will be found in Part IV. 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 125 

Diagram of Connections. 
The general arrangement of instruments and a diagram of the 
connections for the service tests are given in Fig. 44. The in- 
struments used were similar to those already described in Chap- 
ter II, and the general method of conducting the tests was also 
similar to that outlined in Chapter 11. 

Data Sheets. 
In collecting the original data a blank form was used somewhat 
similar to that shown in Fig. 118. Each observer recorded his 
observations on forms of this kind, and which were collected 
together from time to time during the tests. The forms were 
later bound together, and arranged in book form. 

Weight of Equipment. 

The weight of the car equipped, but without load, was 20 tons 
or 40,000 lbs. . In addition to this the instrument equipment 
weighed 300 lbs., and there was an average number of eight 
observers. The total weight of the car with test equipment and 
observers (the latter estimated at 150 lbs. each) was 41,500 lbs. 
The average passenger load during the tests was 21, making a 
weight of 3,150 lbs. The total average weight was therefore : 

Car equipped for regular sendee 40,000 lbs. 

Motorman and conductor 300 lbs. 

Test corps 1,200 lbs. 

Instruments 300 lbs. 

Average passenger load 3,150 lbs. 

Total 44,950 lbs. 

or practically 22J tons. 

WORKING UP THE RESULTS. 

The results of the tests have been briefly set forth in the 
synopsis. The arrangement of the apparatus, the diagram of 
connections, the instruments used, and the data taken have been 
discussed above. The methods used in working up the results 
will now be considered. 

As in the service tests on the single-truck city car, it was not 
only important to take certain data simultaneously, but it 



126 



ELECTRIC RAILWAY TEST COMMISSION 



was also necessary that these data be taken at certain time 
intervals, and that the time of the start and stop of the .car 
should be accurately known with respect to these time inter- 
vals. It was only by proceeding in this way that the exact 
relation of all data could be obtained. 

In working up the data each test was divided into a number 
of round trips, over the Park Avenue line, with the Tower Grove 
Park loop as the starting point. These round trips were num- 
bered consecutively, and the times of leaving and arriving at the 



BeLL 




CoNTR OLLER 



To Motors ^D 
Starting /Prj. 



Marker 



[^Lightning 
ArrcstcH 



Storage 



Batteky 



RE-s/sTAivce 



rA/W\AA/ 




A/.V. 



Switch 

C^oNTACT Points '^"^ USEO 
For Gctting Resistance" 
Between Commutator Seg/^ents 

Fig. 44-. — Diagyam of Connections, Service Tests of Double-Tfucft City Car. 



Tower Grove Park loop were accurately obtained. The dis- 
tance traversed in each of these round trips was 10.53 miles, 
and each test included an average of 10 of these trips. The 
time required for the round trip in each case was obtained 
from the start and stop data, as was also the time of lay- 
over at the Tower Grove Park loop. According to the estab- 
lished schedule upon which the car was operated, a lay-over of 
four minutes was fixed for certain trips of the day's run. This 
lay-over permitted of the reestabhshment of the schedule in 
case of blockades and other delays which arise under ordinary 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 127 

conditions of service, and of the taking of temperature readings 
at intervals throughout the tests. 

The Hne pressure readings, which were taken every five sec- 
onds, were averaged for each round trip. The average current 
for each round trip was obtained by integrating the current 
curves for a particular trip. In obtaining both the average volts 
and the average amperes, the total time from start to stop of a 
round trip was considered in each case. 

The average power was obtained by multiplying together the 
average line pressure and the average current for a given trip. 
Here also the average has been taken for the total period of time 
of a given trip from the start to the stop at the Tower Grove 
Park loop. In a similar manner, the energ}^ for a roimd trip in 
kilowatt hours has been obtained by multiplying together the 
average watts by the total time in hours elapsing from the start 
to the stop of a roimd trip. 

A careful record was made throughout the test of the actual 
number of passengers getting on and off of the car at each stop. 
These data permitted of obtaining the total number of passen- 
gers carried for each round trip, as well as the average number 
of passengers per trip. 

The energy per car-mile in kilowatt hours was obtained by 
dividing the total energy in kilowatt hours per roimd trip by 
10.53, which is the actual length of a roimd trip in miles. 

The energ}^ per ton mile in kilowatt-hours was obtained by 
dividing the energy per car-mile by the total weight of the car, 
including the observers and the average number of passengers 
for the trip. The total weight was approximately 22J tons, as 
previously stated. The energy required per round trip per pas- 
senger carried was obtained by dividing the total energy taken 
in a round trip in watt-hours by the total number of passengers 
and observers carried during the trip. 

The average length of run in feet from start to stop was ob- 
tained for each trip by dividing the total distance traversed by 
the number of stops, these data having been carefully recorded 
in each case. The average interval of run from start to stop, 



128 ELECTRIC RAILWAY TEST COMMISSION 

was obtained by dividing the actual running time of a round trip 
by the total number of stops for the trip. The stops per mile 
were obtained for each trip by dividing the total number of 
stops by 10.53, which was the total distance in miles. The aver- 
age interval of stop in seconds was obtained by dividing the total 
number of seconds for stops during the round trip by the num- 
ber of stops. The schedule speed in miles per hour was calcu- 
lated by dividing the total distance traversed in miles for a 
round trip by the actual time in hours elapsing from the start 
to the stop for each trip. 

The average running speed (not including stops) in miles per 
horn: was obtained by dividing the total length of a round trip 
in miles by the actual running time (deducting all stops) for the 
given round trip. 

As previously stated, temperature measurements were made at 
intervals throughout the day. These measurements consisted of 
readings of the resistances of the armatures of each of the four 
motors by the "fall of potential" method. This consisted essen- 
tially in sending a known current through the armature of the 
motor by means of a storage battery, the trolley circuit being 
cut off during the time the measurements were taken. The 
pressure drop across the commutator bars was read on a milli- 
voltmeter, the current in the armature being recorded at the 
same time. Measurements of this kind were taken each day 
before the car left the barns, and at the close of the test, as well 
as at intervals throughout the tests. 

The temperature of the outside air was also recorded when- 
ever armature resistance measurements were made. From 
these data the resistances of the armatures were computed, and 
the rise in temperature at a given time of the day was deter- 
mined. The final average rise of temperature for the four arma- 
tures at the close of each test was computed in accordance with 
the rules of the American Institute of Electrical Engineers, and 
is recorded on the log sheet accompanying the detailed data of 
each test. 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 129 

Results of the Tests. 

Some of the more important numerical results of the various 
service tests made of the double-truck city car are shown in 
tabular form in the synopsis at the beginning of the chapter. 

It has been found impossible to represent the results of all the 
tests graphically. The more detailed data for each of these ser- 
vice runs are here sho^m in tables, which are supplemented by 
log sheets similar to those accompanying the gr^^phical repre- 
sentations of the results of the service tests of the single-truck 
city car given in Chapter II. In these tables will be found the 
detailed data for each trip of the various tests. The average 
data for the day, together with other general items showing 
the conditions under which a test was run, will be foimd in the 
log sheets accompanying the tables. 

THE GRAPHICAL LOG. 

While it has not been considered possible to represent graphi- 
cally the results of the various service tests made upon the 
double-truck city car, it has been thought desirable to show in 
this manner the results of a single trip which has been taken as 
typical of the conditions existing throughout the entire series 
of runs. The trip chosen for this purpose (which was selected 
more or less at random) is one-half of trip No. 7 of August 24th, 
and it covers the distance from the Third Street loop in 
the center of the city of St. Louis, to the Tower Grove Park loop 
at the end of the Park Avenue line. 

Time has been taken as a base in making up this graphical 
log. The profile is consequently not shown at this point, but 
will be found in Part IV, where the braking results of these tests 
are graphically shown on a distance base. 

The Speed Curve. 

In taking the original data a Boyer railway speed recorder 

was employed for speed measurements. In addition to this a 

small magneto-generator was driven by the car axle, and the 

pressure generated was read by means of a milli-voltmeter. The 



130 ELECTRIC RAILWAY TEST COMMISSIOM 

Boyer railway speed recorder gave a record of the speed on a 
distance base. The pressure readings of the magneto-generator 
were taken at the stroke of the five-second bell, and therefore 
would give the speed on a time base. In addition to these 
speed data, the actual time of passing the farther crossings of the 
street intersections was accurately recorded. 

In working up the results it was found that no dependence 
could be placed upon the data obtained from the magneto-gen- 
erator. This was due to the particular apparatus used, and not 
to this general method of obtaining speed data. The service 
tests upon the double-truck city car were the first tests of this 
nature undertaken by the Commission, and the magneto- 
generator used in these tests was in later tests replaced by 
an "Apple" generator, which gave very satisfactory results. 

Because of the fact that the data obtained from the magneto- 
generator could not be depended upon, it was necessary to fall 
back on the Boyer railway speed recorder and the data showing 
the time of passing the farther crossings of the street intersec- 
tions, for speed measurements. The Boyer railway speed re- 
corder was calibrated in position by jacking up the car with the 
truck in position, and rvmning the wheels at different speeds, 
simultaneous readings being taken of the revolutions of the 
wheels, and of the indicating gage of the recorder. At the 
same time a record was taken on the tape of the recording 
instrument. In working up the speed curve the Boyer rec- 
ord was plotted to a larger scale and integrated between street 
intersections. The average speed thus obtained was checked 
by the distance traversed, and by the elapsed time, as shown 
by the other data. 

After having made certain that the distance-speed curve was 
correct, it became necessary to change this over to a time-speed 
curve. This was done by first laying off on a time base the ac- 
tual time at which the car passed the farther crossings of street 
intersections, and also the actual time of start and stop where 
stops were made. The various loops of the distance-speed curve 
were then divided into a number of sections, and these sections 





3:30 



(To face page 130) 





Time 3.00 p.m. 3:02 



3:04 



a-06 



^08 



GMO a;12 ^il4 - 

,I''lG. 10— Graphical Log ut Oile-Uall Trip c 



3;i6 

I Park Avo. Line. St. 



3.-18 



3:20 



3:22 



3:24 



3:26 



3:28 



3:30 



SERVICE TESTS OF A DOUBlE-TnUCK CITY CAR 131 

were each integrated independently and the average speed ob- 
tained for each section. As the base of the loop up to the ordi- 
nate considered, showed the distance traversed to this point, this 
distance was obtained and was divided by the average speed. 
This gave the time which had elapsed up to the point con- 
sidered. This period of time was laid off on the time-speed 
curve, and the average speed for the period was assumed to 
occur at one-half the elapsed time. This speed value was then 
plotted on the time-speed curve. By proceeding in this man- 
ner, step by step, the various points on the time-speed curve 
were obtained from the distance-speed curve. Where the curve 
was not shown sufficiently in this way, additional data were 
obtained to show intermediate points. The time-speed curve 
was then plotted. 

The Pressure Curve. 

The pressure curve was obtained by plotting the five-second 
readings for the entire run, and straight lines were drawn be- 
tween the consecutive points. 

The Current Curve. 
The current curve was replotted directly from the current 
record produced by the recording ammeter, which record was 
already on a time base. 

The Power Curve. 
The power curve was obtained by multiplying together the 
instantaneous values of the line pressure and the current as 
shown by the recording ammeter, for each five-second interval 
throughout the run. These points were plotted, and the inter- 
mediate points filled in according to the general shape of the 
current curve, due consideration being given to any variations 
in pressure during the interval. 

The Distance Curve. 
The distance curve was obtained directly from the data show- 
ing the time of passing the farther crossings of the street inter- 
sections. Where a stop was made, the time of stop is shown by 
a line parallel to the base on the distance curve. 



132 ELECTRIC RAILWAY TEST COMMISSION 

The Energy Curve. 

The curve showing the total energy consumed up to a certain 
point on the trip was obtained by integrating the ammeter curve 
up to this point, and multiplying the ampere-hours thus ob' 
tained by the average pressure up to the point considered. 
Where a stop occurs, the energy curve shows a line parallel 
to the base for the time of stop. No attempt was made to 
show the instantaneous variations in the form of the energy 
curve between the street intersections. The increase in energy 
taken is shown by a straight line from one street to the next in 
each case. 

This graphical log is shown opposite page 138 and is Plate I, 
Fig. 45. The general log for this particular run is given in con- 
siderable detail. This general log shows the general conditions 
under which this particular run was made, in a manner similar 
to the explanatory logs accompanying the tabulated general 
results of the various tests. In this log, for a specific run will 
be foimd additional data concerning maximum values of speed, 
current, and power. 

In order to show the relations of the maximum values of speed, 
current, and power to the average values, the following plan was 
employed. From the time-speed, time-current, and time- 
power curves, the maximimi values of all loops were obtained, 
and these were averaged. This gave the average maximum 
values of the various quantities. Finally, the highest value 
which each of these attained during the tests was obtained 
in order to indicate the extreme maximimi values and their 
relations to the average maximimi values. 

GENERAL LOG SHEET OF TEST NO. 6. 
(Independent Motor-Compressor Air Brake System.) 

Date, Thursday, August 18th, 1904 ; Place, St. Louis, Mo.; 
Route, Park Avenue line of St. Louis Transit Company, running 
from Tower Grove Park to Third Street and Washington 
Avenue ; Weather, unsettled, rainfall of 0.16 inch between 6.27 
A.M. and 6.20 p.m. The average air temperature during the 
run was 22.6° C. or 72.7° F. Condition of track, dry at first but 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 133 

wet during the greater part of the test. Test started, 7.02 a.m. 
Test stopped, 7.05 p.m. Total duration of test, 12.05 hours. 

Average Data for Day. 

Passengers. — Total number of passengers per round trip, 141 ; 
average number of passengers on car, 35. 

Pressure Measurements. — Line pressure, 488.4 volts. 

Distance Measurements. — Length of a round trip, 55,600 ft. 
or 10.53 miles; stops per mile, 4.1; stops per round trip, 43; 
length of a single run (start to stop), 1264 ft. 

Time Measurements. — Interval of round trip (start to stop), 
66.5 minutes; interval of lay-over at the Tower Grove Park loop, 
2.0 minutes; interval for total stops for trip, 6.2 minutes; run- 
ning time for trip, 60.3 minutes; interval of round trip (start to 
start), 68.5 minutes; interval of a single run (start to stop), 82.2 
seconds; interval of stop, 8.6 seconds; interval of a single run 
(start to start) 90.8 seconds; interval of a run (start to start and 
including all stops for temperature readings and lay-over at the 
Tower Grove Park loop), 93.4 seconds. 

Speed Measurements. — Average speed (actual running time), 
10.47 miles per hour; schedule speed (including stops during 
trip), 9.50 miles per hour. 

Current Measurements. — Average current (for roimd trip), 
53.3 amperes; average current (actual running time), 58.8 am- 
peres; average current for the day, 51.7 amperes. 

Power Measurements. — Average power (for round trip), 
26,032 watts; average power (actual running time), 28,708 
watts; average power for the day, 25,272 watts. 

Energy Measurements. — Average energy per round trip, 
28,852 watt-hours; average energy per run (start to stop), 656 
watt-hours; average energy per car-mile, 2740 watt-hours ; aver- 
age energy per ton-mile, 122 watt-hours ; average energy per 
passenger carried (total for trip), 203 watt-hours. 

Temperature Measurements. — (Degrees centigrade), (Con- 
ditions at the end of the run), temperature of outside air, 23.5°; 
average temperature of motor armatures, 68.0° ; average tem- 
perature rise above an air temperature of 25.° C, 44.8°, 



134 



ELECTRIC RAILWAY TEST COMMISSION 



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SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 135 

GENERAL LOG SHEET OF TEST NO. 7. 
(Air Brake System with Independent Motor-Compressor.) 

Date, Wednesday, August 24th, 1904; Place, St. Louis, Mo.; 
Route, Park Avenue line of St. Louis Transit Company, running 
from Tower Grove Park to Third Street and Washington 
Avenue ; Weather, clear, no rain. The average air tempera- 
ture for the day was 27.5° C. or 8L5° F. Condition of track, dry 
and clean. Test started, 6.59 a.m. Test stopped, 7.11 p.m. Total 
duration of test, 12.2 hours. 

Average Data for Day. 

Passengers Carried. — Total number per round trip, 131; 
average number on car, 32. 

Pressure Measurements. — Line pressure, 471.8 volts. 

Distance Measurements. — Length of a round trip, 55,600 ft. 
or 10.53 miles; stops per mile, 4.5; stops per round trip, 47; 
length of a single run (start to stop), 1158 ft. 

Time Measurements. — Interval of round trip (start to stop), 
67.8 minutes; interval of lay-over at the Tower Grove Park 
loop, 2.8 minutes; interval for total stops for trip, 6.7 minutes; 
running time for trip, 61.1 minutes; interval of round trip (start 
to start), 70.6 minutes; interval of run (start to stop), 76.4 sec- 
onds; interval of stop, 8.6 seconds; interval of a single run 
(start to start), 85.0 seconds; interval of run (start to start, and 
including all stops for temperature readings and lay-over at 
Tower Grove Park loop), 88.3 seconds. 

Speed Measurements. — Average speed (actual running time), 
10.34 miles per hour; schedule speed (including stops during 
trip), 9.32 miles per hour. 

Current Measurements. — Average current for round trip, 
53.3 amperes; average current (actual running time), 59.1 
amperes; average current for the day, 51.2 amperes. 

Power Measurements. — Average power (for round trip), 
25,147 watts; average power (actual running time), 27,883 
watts; average power for the day, 24,156 watts. 

Energy Measurements. — Average energy per round trip 



136 



ELECTRIC RAILWAY TEST COMMISSION 



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SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 137 



28,416 watt-hours; average energy per run (start to stop), 592 
watt-hours; average energy per car-mile, 2698 watt-hours; 
average energy per ton-rnile, 120 watt-hours; average energy 
per passenger carried (total for trip), 217 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 8. 
(Air Brake System Employing Storage Air.) 

Date, Monday, August 29th, 1904 ; Place, St. Louis, Mo.; 
Route, Park Avenue line of St. Louis Transit Company, running 
from Tower Grove Park to Third Street and Washington 
Avenue; Weather, clear, no rain. The average air tempera- 
ture for the day was, 25.5° C. or 77.8° F. Condition of track, 
dry and clean. Test started, 7.38 a.m. Test stopped, 7.05 p.m. 
Total duration of test, 11.45 hours. 

Average Data for Day. 

Passengers Carried. — Total number per round trip, 130; 
average number on car, 32. 

Pressure Measurements. — Line pressure, 475.6 volts. 

Distance Measurements. — Length of a round trip, 55,600 ft. 
or 10.53 miles; stops per mile, 5.9; stops per round trip, 63; 
length of a single nm (start to stop), 869 ft. 

Time Measurements. — Interval of round trip (start to stop), 
69.3 minutes; interval of lay-over at Tower Grove Park loop 
2.0 minutes; interval of total stops for round trip 6.2 minutes; 
rimning time for trip, 63.1 minutes; interval of round trip (start 
to start), 71.3 minutes; interval of a single run (start to stop), 
59.1 seconds; interval of stop, 5.9 seconds; interval of a single 
run (start to start), 65.0 seconds; interval of run (start to start, 
and including all stops for temperature readings and lay-over at 
the Tower Grove Park loop), 66.8 seconds. 

Speed Measurements. — Average speed (actual running time), 
10.01 miles per hour; schedule speed (including stops during 
run), 9.12 miles per hour. 

Current Measurements. — Average current for round trip, 53.2 



138 



ELECTRIC RAILWAY TEST COMMISSION 



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SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 139 

amperes; average current (actual running time), 58.4 amperes; 
average current for the day, 51.7 amperes. 

Power Measurements. — Average power for round trip, 
25,292 watts; average power (actual rimning time), 27,775 
watts; average power for the day, 24,589 watts. 

Energy Measurements. — Average energy per roimd trip, 
29,212 watt-hours; average energy per run (start to stop), 457 
watt-hours; average energy per car-mile, 2774 watt-hours; aver- 
age energy per ton-mile, 123 watt-hours; average energy per 
round trip for each passenger carried (total for trip), 225 watt- 
hours. 



GENERAL LOG SHEET FOR GRAPHICAL LOG OF 

TEST NO. 7. 

(Second Half of Trip No. 7.) 

Date, Wednesday, August 24th, 1904; Place, St. Louis, Mo.; 
Route, from Third Street and Washington Avenue to the Tower 
Grove Park loop, on the Park Avenue line of the St. Louis 
Transit Company; Time of run, 3.00 p.m. to 3.32 p.m.; Weather, 
clear, no rain; Condition of track, dry and clean. 

Data for Trip. 

Passengers Carried. — Total number for trip, 62 ; average 
number on the car, 26. 

Pressure Measurements. — Line pressure, 501 volts; maximum 
line pressure, 505 volts; minimum line pressure, 440 volts. 

Distance Measurements. — Length of trip, 27,800 ft. or 5.26 
miles; stops per mile, 4.2; stops for the trip, 22; length of a 
single run (start to stop), 1202 ft. 

Time Measurements. — Interval of trip (start to start), 32.0 
minutes; interval for total stops for the trip, 122 seconds; 
running time for the trip, 29 minutes, 58 seconds; average inter- 
val of run (start to stop), 78.2 seconds; average interval of run 
(start to start), 83.0 seconds; average interval of stop, 5.55 
seconds, 



140 



ELECTRIC RAILWAY TEST COMMISSION 



Speed Measurements. — Average speed (actual running time), 
10.05 miles per hour; schedule speed including stops 9.87 miles 
per hour; maximum speed 17.5 miles per hour; total number of 
rmis, 23. 

Current Measurements. — Average current for the trip, 54.85 
amperes; average current (actual running tim^e), 58.5 amperes- 
average maxinmm current, 130 amperes; maximum current, 245 
amperes ; place where maximum current occurred, between Clark 
Avenue and Austin Street. 

Povjer Measurements. — Average power for trip, 27,790 watts; 
average power actual running time, 29,650 watts; average maxi- 
mum power, 64,800 watts; maximum power, 120,000 watts; 
place where maximum power occurred, between California and 
Ewing and between Theresa and Grand. 

Energy Measurements. — Total energy for the trip, 14.792 
kilowatt-hours; energy per run (start to stop), 643 watt-hours; 
energy per car-mile, 2.81 kilowatt hours; energy per ton-mile, 
125 watt-hours; energy per passenger carried (total for trip), 
283 watt-hours. 



Discussion of Results. 

The service tests on the double-truck city car give data which 
may be studied from several different standpoints. In the first 
place, they afford information as to the performance of a car 
run upon a schedule in practical operation in one of the large 
cities of the country, the car tested being one of 1500 similar 
cars run in regular service. In the second place, the data allow 
of a comparative study of the performance of the car when 
operated over the same route and on the same schedule, under 
conditions of a dry track and a clear day, as against those of a 
wet track and a rainy day. A comparison of the general data of 
this chapter with those of Chapter II, also leads to some inter- 
esting deductions. 

Tests Nos. 6, 7, and 8 were performed on three different days, 
with several days intervening between tests in each case. While 
the data for the individual runs of the various tests differ very 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 141 

materially, it is interesting to note that the general data for 
the day agree very closely for the three tests. In this connec- 
tion it is to be remembered that the same general schedule was 
adhered to throughout all three tests, which made the total 
duration of the test, the length of a round trip, and the interval 
of a round trip, approximately the same in all tests. 

The latter condition was not the same in all tests, as the actual 
time of a round trip was somewhat dependent upon the number 
of stops per mile, which in turn was dependent upon the condi- 
tions of service. In Test No. 6, the average length of a single 
run was 1264 ft.; in Test No. 7, this distance was 1158 ft.; and 
in Test No. 8, stops were made every 869 ft. While the average 
duration of stop was somewhat less in Test No. 8 than it was 
in the other two tests, the fact that the number of stops per mile 
was considerably greater, is, in itself, a sufficient explanation of 
the increased interval of round trip in Test No. 8. While Tests 
Nos. 6 and 7 did not differ greatly either in stops per mile or in 
duration of round trip, it is to be observed that the stops per 
mile were somewhat the greater in Test No. 7, which fact ac- 
counts for the slightly increased duration of round trip. 

It is interesting to observe that, while the passengers on the 
car at any one time varied greatly, and while the number per 
trip was radically different at different periods of the day, the 
average number per round trip was 141 in Test No. 6, 131 in 
Test No. 7, and 130 in Test No. 8. More remarkable still is the 
uniformity in the average number of passengers carried in the 
three days, this number being 35, 32, and 32 in the respective 
tests. 

It is to be expected that the average line pressure would not 
differ greatly in the three tests, and this is seen to be the case, 
the values being 488, 472, and 476 respectively. On the con- 
trary, a great uniformity of average current is not to be expected, 
as the individual trips showed a considerable variation in the 
average value of the current. Notwithstanding this fact, the 
average value of the current is almost identical in the three 
tests, being exactly the same in Tests Nos. 6 and 7. With such 



142 ELECTRIC kAILWAY TEST COMMISSION 

uniformity both in average current and in average pressure, it is 
to be expected that the average power during a round trip v/ill 
be nearly the same for all tests, and this is seen to be the case. 

The average interval of run from start to stop is seen to vary 
from 82 seconds in Test No. 6, to 59 seconds in Test No. 8. This 
follows from the fact that the number of stops per mile was con- 
siderably greater in Test No. 8 than in Test No. 6. This fact 
also explains the similar discrepancy in the average interval of 
run from start to start in the three tests. It is interesting to 
note, also, the uniformity of the schedule speed in the three 
tests, as well as that of the average speed during actual running 
time. 

From the fact that both the duration of a round trip and the 
average power expended during the trip are very uniform in the 
three tests, it is to be expected that such data as average watt- 
hours per trip and average kilowatt-hours per car-mile will agree 
closely in the three tests, and this is seen to be the case. 
p\irthermore, as the average number of passengers carried does 
not vary appreciably in these tests, it is also to be expected 
that the average watt-hours per ton-mile and the average watt- 
hours per passenger (total), will agree closely. The data of the 
tests fully corroborate these deductions. 

While considerable time was spent in the construction of 
apparatus for the electrical measurement of the temperatures of 
the motors, and while the data relating to these temperatures 
were carefully taken, these data have not been found to be 
thoroughly consistent and reliable in the series of tests under 
consideration. As the time intervals available for taking tem- 
perature data were very short, no thermometer readings were 
made, and for this reason there is no check on the temperature 
data as calculated from the electrical readings. Although the 
results are not very consistent, they have nevertheless been 
introduced into the Report. 

Another thing to be observed in connection with the general 
data of the three tests, is that there is very little difference in 
the conditions of operation on a clear day and on a wet day. A 



SERVICE TESTS OF A DOUBLE-TRUCK CITY CAR 143 

few more passengers are carried on a wet clay and they are car- 
ried for a greater average distance. In other respects, the three 
tests show very similar results. 

A brief discussion showing a comparison of the performances 
of the double-truck and the single-truck city cars, is of interest. 
In this connection, it is well to note that the total distance trav- 
ersed in a single run averages 1097 ft. in the tests with 
the double-truck car, as against 791 ft. with the single-truck 
car. 

A comparison of the general data obtained for the double- 
truck city car with the results given in Chapter II for the single- 
truck city car, shows that the duration of the tests for the 
double-truck car averaged 11.9 hours, as against 7.1 hours for 
the single-truck car. While the latter was run on a uniform 
schedule, the length of single run being 791 ft. and the schedule 
speed being 10.5 miles per hour, it is interesting to note that the 
double-truck car averaged 1097 ft. per single run and the sched- 
ule speed averaged 9.3 miles per hour for the three tests. The 
general conditions of service were therefore in favor of the 
double-truck car, as the length of a single run was greater and 
the schedule speed less, than for the single-truck car. 

An inspection of the pressure values shows that the line pres- 
sure was the higher in the tests with the single-truck car. The 
current values cannot be compared directly for the two cars, 
since these data are shown for the time the power was actually 
taken from the line in the tests on the single- truck car, whereas 
they have been averaged throughout the run in the tests with 
the double-truck car. The power, however, is given both for 
the time the power was actually taken, and also for the total 
period of the regular schedule in the data for the single-truck 
car. It is seen from this latter data, that the average power is 
approximately 24,000 watts as against approximately 25,500 
watts for the double-truck car. A comparison of the kilowatt- 
hours per car-mile shows an average of 2.31 for the single-truck 
car, as against 2.74 for the doubl.e-truck car. This result is to 
be expected, from the fact that the average power is somewhat 



144 ELECTRIC RAILWAY TEST COMMISSION 

greater and the schedule speed somewhat less for the double- 
truck car than for the single-truck car. 

The average watt-hours per ton-mile is 162 for the single- 
truck car, as against 122 for the double-truck car. This results 
from the fact that, while the energy per car-mile was not greatly 
less for the single-truck car, the weight of this car was but little 
more than two-thirds that of the double-truck car. 

The comparison of the two cars on the basis of average watt- 
hours per passenger carried (total), can only be obtained by 
making some assumptions as to the schedule of operation of the 
single-truck car. These assumptions would have to include 
the total number of passengers carried, as well as the total 
length of a round-trip. Both of these factors might vary widely 
in different cases. 






CHAPTER IV. 
SERVICE TESTS OF AN INTERURBAN CAR. 



Objects of the Tests. 

The principal object of these tests was to study the general 
performance of a typical interurban car when operated under 
normal conditions in a locality where interurban railways have 
been in successful operation for a considerable period of time. 
The tests included such measurements as those of speed, cur- 
rent, pressure, power, energy, and motor heating. The car was 
tested only on clear days and on a dry track, both when oper- 
ated alone, and when hauling a trailer. Consequently, com- 
parative data was obtained as to the performance of the car 
under these conditions. 



Synopsis of Results. 

Table XI. — Synopsis of Results. Service Tests on Interurban Car. 



Weather Conditions 

Total Duration of Test (Minutes) 

Total Time of Lay-over (Minutes) . . . 

Total Running Time Including Ordi- 
nary Stops (Min.) 

Total Distance Traversed (Miles) 

Equivalent Passenger Load 

Ave. Line Pressure (Volts) ^ 

Ave. Current (Amperes) ^ 

Ave. Power (Watts) ^ 

Ave. Length of Run in Cities (Miles) ^ 

Ave. Length of Run between Cities 
(Miles) 2 



Test 


Test 


Test 


No. 9. 


No. 10. 


No. 11. 


Clear 


Clear 


Clear 


317.25 


236.50 


288.33 


132.00 


38.58 


35.06 


185.25 


197.92 


253.26 


93.90 


95.02 


113.10 


30 


30 


70 


451.4 


471.5 


472.5 


220.5 


216.6 


265.0 


103,300 


96,100 


122,700 


0.68 


1.02 


1.09 


5.84 


5.10 


5.15 



Test 
No. 12. 

Clear 
284.33- 

57.91 
226.42 

113.10 

30 

449.0 

213.5 

97,300 

1.52 

5.75 



^ Average taken for actual running time, including ordinary stops, but not 
lay-over. 

2 Indianapolis, Anderson, and Mimcie. 

^ Average of all motors taken at the end of the test. 

145 



146 



ELECTRIC RAILWAY TEST COMMISSION 



Table XI. - 


— Continued. 


- 






Test 


Test 


Test 


Test 




No. 9. 


No. 10. 


No. 11. 


No. 12. 


Ave. Stops Per Mile in Cities 


1.48 


0.97 


0.92 


0.66 


Ave. Stops Per Mile between Cities . . 


0.17 


0.20 


0.19 


0.17 


Ave. Speed (Miles per Hour) ^ 


30.41 


28.84 


26.80 


29.95 


Ave. Speed in Cities (Miles per Hour) ^ ^ 


12.55 


12.58 


11.45 


12.33 


Ave. Speed between Cities (Miles per 


38.63 


36.50 


33 . 80 


38.55 


BoutY 2 










Kilowatt-Hours Per Car-Mile 


3.40 

85.6 

10,632 


3.34 

84.4 

10,558 


4.58 
73.8 
7,407 


3.24 


Watt-Hours Per Ton-Mile 


81.8 


Watt-Hours Per Equivalent Through 


12,243 


Passenger 










Temp. Rise of Motors above an Air 


46.1 


59.9 


78.8 


69.7 


Temp, of 25° C.^ 











Test No. 9. Feb. 2, 1905. Dry Track. No Trailer. Four Hot Boxes. 
Run from Muncie city limits to Indianapolis; Indianapolis to Anderson. 

Test No. 10. Feb. 3, 1905. Dry Track. No Trailer. Two Hot Boxes. 
Run from Anderson to Muncie; Muncie to Indianapolis; Indianapolis to 
Anderson. 



_ Test No. 11. Feb. 4, 1905. Dry Track, 
cie to Indianapolis and return to Muncie. 

Test No. 12. Feb. 4, 1905. Dry Track, 
to Indianapolis and return to Muncie. 



One Trailer. Run from Mun- 



No Trailer. Run from Muncie 



^ Average taken for actual running time, including ordinary stops, but not 
lay-over. 

2 Indianapolis, Anderson, and Munice, 

^ Average of all motors taken at the end of the test. 



General Conditions of the Tests. 



The service tests upon the interurban car were made upon the 
hues of the Indiana Union Traction Company, which, consid- 
ered from the standpoint of the number of miles of track in 
operation, constitute what is probably the largest interurban 
railway system in the country at the present time. The prin- 
cipal cities connected by the system are Indianapolis, Anderson, 
Muncie, Marion, Alexandria, Tipton, Kokomo, Peru, Logans- 
port, and Noblesville. The offices of the company are at Ander- 
son, as are also the main power house and the principal car 
shops. A map of the system is given in Fig. 46. It comprises 
in all approximately 262 miles of track, of which 211 miles are 



SERVICE TESTS OF AN INTMURBAN CAR 147 

interurban lines, and the remaining 51 miles are city lines. 
The lengths of the lines between the various cities are as 
follows : 

Indianapolis to Anderson • 39 miles 

Anderson to Muncie 18 miles 

Anderson to Marion 34 miles 

Alexandria to Tipton 20 miles 

Indianapolis to Kokomo 57 miles 

Kokomo to Logansport 24 miles 

Kokomo to Peru 19 miles 

Total 211 miles 

The track mileage is divided between the various cities as 
follows : 

Anderson 11.6 miles 

Marion 14.8 miles 

Mmicie 15.4 miles 

Elwood 6.4 miles 

Alexandria , 1.0 miles 

Jonesborough 1.8 miles 

Total 51. u miles 

The system consists largely of single track and is built upon 
a private right-of-way between the cities, the right-of-way being 
from 60 to 100 ft. in width. The road-bed is of the most sub- 
stantial type, the ballast being 14 in. deep, and laid upon a 
bank 16 ft. in width. Oak ties, 6 in. by 8 in. by 8 ft. in size 
are spaced with 24 in. between centers, and upon these are laid 
80-lb. rails connected by 250,000 cm. protected rail bonds, and 
in addition the rails are cross-bonded near all the special work. 

The power is supplied to the system from the power station at 
Anderson at 15,000 volts over the Eastern division, and at 30,000 
volts over the Northern division. The power is received at 
substations suitably distributed along the lines, which contain 
transformers and rotary converters for reducing the pressure to 
600 volts and converting the power to direct current. The 
general plan of the distribution is shown in Fig. 46. 

THE MUNCIE-ANDERSON-INDIANAPOLIS DIVISION. 

The service tests upon the interurban car were conducted 
upon the Muncie division of the lines of the Indiana Union Trac- 



148 



ELECTRIC RAILWAY TEST COMMISSION 




Fig, 46. — Map of System of Indiana Union Traction Company, 



SERVICE TESTS OF AN INTERURBAN CAR 



149 



tion Company. This division, as shown in Fig. 46, connects the 
cities of Muncie, Anderson, and Indianapohs. IndianapoUs has 
a population of approximately 200,000, while the other two cities 
have a population of about 30,000 each. The division, which 
is the original line of the system, runs through a rich farming 
country, and besides connecting the cities above mentioned, 
passes through a number of towns and villages, varying in size 
from 5,000 to 2,500 inhabitants.^ It is supplied with power 
from the following substations, which have the equipments 
specified. 

LOCATION or SUBSTATIONS AND EQUIPMENTS. 



Sub- 
station. 


INIlLES 
FROM 

Ander- 
son. 


Trans- 
mission 
Voltage. 


Number 

OF 

Step- 
down 
Trans- 
formers. 


Capa- 
city OF 
Each 

IN 

Kilo- 
watts. 


Number 

OF 

250 K.w. 
Ro- 

TARIES. 


Capacity of 

Storage 

Battery in Amp. 

ON 8 HR, Rate 

OF Discharge. 


Anderson . 
Dale^•ille . . 
Muncie . . . 
Ingalls . . . 
Lawrence . 




7.1 
17.1 
14.5 
28.9 


375 
15,000 
15,000 
15,000 
15,000 



4 
4 
4 

7 


87i 
87i 
175 

87i 
87i 


3 
1 
2 
1 
2 


100 
40 
80 
40 
40 



THE CAR TESTED. 

The car selected for test was fully described in Chapter I. It 
was numbered "284" and was a new car of the most recent type 
employed by the company for its limited service. 



THE CONTROL AND BRAKE EQUIPMENT. 

As stated in Chapter I, the Westinghouse Pneumatic System 
of train control was used on car "284" when these tests were 
made. A complete description of this system of control is given 
in Part III, in connection with the acceleration tests made on 
this car. 

* More detailed descriptions of the lines of the Indiana Union Traction 
Company will be found in the Street Railway Journal, Vol. 24, 1904, page 
1064, and Vol. 18, 1901, page 821. 



150 



ELECTRIC RAILWAY TEST COMMISSION 



The car was equipped with the Westinghouse "straight air" 
system of braking which is more completely described in Part 
IV, in connection with the braking tests of car "284." 

The average power taken and the total energy consumed per 
trip hi operating the controller, are considered in Part III, while 
the corresponding values relating to the operation of the air brake 
are shown in Part IV. 



MOTIVE POWER EQUIPMENT. 

The motive power equipment of car "284" has already been 
described in a general way in Chapter I. As the service capa- 



100 2000 



S0 1800 



80 1600 



70 1400 



60 1200 



60 1000 



^ 40 800 



30 600 



20 400 



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Fig. 47. — General Performance Curves of Westinghouse No. 8 Motors. 

city of the motors has a very important bearing upon the test 
considered in the present chapter, their characteristic features 
of operation are here briefly discussed. 

The general performance of the Westinghouse No. 85 motors 
with a gear ratio of 27 to 47, is shown in Fig. 47. The curves 
are taken from data furnished by the manufacturers and show the 
speed, tractive effort, and brake horse power with current at 



SERVICE TESTS OF AN INTERURBAN CAR 151 

from 30 amperes to 240 amperes at 500 volts. The total elec- 
trical power input and the efficiency are also shown. The 
manufacturers make the following statements regarding the 
service capacity of these motors : 

" The motor has a continuous capacity of 60 amperes at 300 
volts or of 55 amperes at 400 volts. Under the usual condition 
of railway service, it will carry any load within the range shown 
on the performance curves, provided the integrated heating 
effect does not exceed that caused by the continuous application 
of either of these currents at the corresponding potential. 

*' With a load of 60 amperes at 300 volts or 55 amperes at 400 
volts carried continuously during a shop test, the rise in tempera- 
ture of the motor windings, as measured by thermometer after 
ten or twelve hours, or after a constant temperature has been 
reached, will not exceed 75° C. With equivalent load under a 
moving car the temperature rise should not exceed 55 C. 

" Heavier loads may be carried for shorter periods as indicated 
by the time temperature curve. If, for example, the motor has 
been working at a load equivalent to 60 amperes at 300 volts, 
and has reached a temperature of 75° C, it may then, as shown 
by the curve, carry a load equivalent to the 72 amperes at 300 
volts for IJ hours, with additional rise in temperature not ex- 
ceeding 20° C." 

TOTAL WEIGHT OF CAR ^^284." 

The weight of the car equipped and ready for service was 
74,530 lbs., as stated in Chapter I. The car had a seating capac- 
ity of 48 passengers, and it was estimated that 30 passengers would 
be an average load, exclusive of motorman and conductor. The 
total passenger load on the basis of 150 lbs. for each person would 
then be 4500 lbs. As there was an average of 10 observers on 
the car throughout the tests, a dead load of 3000 lbs. was carried 
to compensate for the weight of 20 additional passengers. The 
main dead load consisted of a number of l^ags of sand, which 
were placed under the seats of the car. The weight of instru- 
ineiits and other appliances amounted to another 450 lbs, Th^ 



152 ELECTRIC RAILWAY TEST COMMISSION 

total load, under the conditions of test, may be summed up as 
follows : 

Weight of car equipped and ready for service .... 74,530 lbs. 

Weight of total dead load 3,000 lbs. 

Weight of total live load (including motorman and 

conductor) 1,800 lbs. 

Total weight 79,330 lbs. 

This total weight is approximately 39| tons. 

THE TRAIL CAR. 

Car "284'^ was still further loaded by car "302" being used 
as a trailer to it in Test No. 3. This car was one of the standard 
interurban trailers used by the Indiana Union Traction Com- 
pany, and its general construction was somewhat similar to that 
of car "284," excepting that it had no vestibules and was con- 
siderably lighter. 

The total weight of the trailer car "302," equipped and ready 
for service, was 39,000 lbs. The seating capacity of this car was 
50 passengers, and a load equivalent to 40 passengers at 150 lbs. 
each was placed on the car. This load consisted of a number of 
bags of sand placed under the seats, and weighing 6,000 lbs. 
The total weight of car "302" was, therefore, 45,000 lbs. or 22 J 
tons. 

General Description of the Tests. 

The four service tests on this car were made on Thursday, 
February 2d, Friday, February 3d, and Saturday, February 
4th, 1905, two tests being made upon the latter day. While the 
car was operated on the same general schedule and over the same 
line in all four runs, the conditions were somewhat different. 

All four tests were made upon the line between Muncie and 
Indianapolis, a distance of 56.55 miles. The car barns and 
shops are at Anderson, which is between Indianapolis and Mun- 
cie, and 18.8 miles from the latter city. The schedule time be- 
tween Muncie and Indianapolis for the limited cars is 2 hours 
and 5 minutes going to Indianapolis, and 2 hours and 10 minutes 
returning to Muncie. The round trip, therefore, consumes 4 



SERVICE TESTS OF AN INTERURBAN CAR 153 

hours and 10 minutes, in addition to the lay-over at Indianapohs. 
The running time of trains on the division at the time the tests 
were made, is shown in Table XII. 

The company operates what are termed first-class or limited 
cars, and second-class or local cars. The limited cars make 
stops only at the various towns along the right-of-way and carry 
no baggage, while the local cars make additional stops at the road 
intersections and carry baggage. The schedule time of the local 
cars between Muncie and Indianapolis is 2 hours and 20 minutes, 
which is 15 minutes longer than the time of the limited cars. 

A^Hiile the tests made with car "284" were run on the same 
schedule as that of any one of the regular limited cars, it was 
necessary to so arrange the schedule as not to interfere with the 
regular passenger service. It was considered advisable to load 
the car with a dead weight rather than attempt to substitute it 
in place of one of the regular limited cars carrying a passenger 
load. The car consequently ran between cars operated on the 
regular schedule, and the running time, relative to the regular 
cars, was so adjusted as to give, as far as possible, a good average 
line pressure thi'oughout each run. 

WEATHER CONDITIONS. 

In the consideration of service tests on interurban cars, it is 
important to know the general weather conditions at the time 
of the tests. Not only should the condition of track be noted, 
but the direction and velocity of the wind and the temperature 
of the air should also be recorded, as these have an important 
bearing upon the power consumption and the heating of the 
motors. On all three days, February 2d, 3d, and 4th, the 
weather was clear and cold, and the track was in good condition 
and free from snow. The direction and velocity of the wind and 
the temperature of the air are given at hourly intervals for each 
of these tests in Table XIII. 

Test No. 9. — This was the first of the service tests on car 
"284," and must be considered more or less as a preliminary rim, 
since four of the axle journals became overheated, even though 



154 



ELECTRIC RAILWAY TEST COMMISSION 



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SERVICE TESTS OF AN INTERURBAN CAR 155 



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156 ELECTRIC RAILWAY TEST COMMISSION 

the temperature of the air was one degree below zero, and a lay- 
over in Indianapolis was imperative. In this test, a run was first 
made from Anderson to Mimcie, and this was followed by a run 
from Muncie to Indianapolis. The intention was to make the 
return trip to Muncie and to run from Muncie back to the shops 
at Anderson. Because of the hot boxes above mentioned, how- 
ever, the return trip was not made to Muncie but the car was 
run into the shops upon reaching Anderson. As a complete 
record was not taken of the run from Anderson to Muncie, it is 
impossible to give data for the complete round trip from Muncie 
to Indianapolis and return for this test. The running schedule 
of this test is shown in Table XXVI. 

Test No. 10. — The axle journals of car "284" were over- 
hauled after the test of Thursday, February 2d, and on Friday, 
February 3d, Test No. 10 was run over the same route and 
schedule as Test No. 9. In this run it was found that two of the 
journals still gave considerable trouble, and consequently the car 
was again run into the Anderson shops instead of returning to 
Mimcie, in order that the troublesome journals might be put in 
shape for the next day's test. In working up the final results, a 
round trip has been considered to have been made from Muncie 
to Indianapolis and return; the first portion of the run, from 
Anderson to Muncie, being considered as having occurred after 
the car had reached Anderson on the return trip. The running 
schedule of this test is given in Table XXVII. 

Test No. 11. — This test was made on Saturday, February 
4th, and a trailer (car No. " 302 ' ) was hauled by car " 284" from 
Muncie to Indianapolis and return. The start from the Ander- 
son shops for Muncie was made at 7.25 a.m., and the start on the 
round trip from Muncie to Indianapolis and return was made at 
9.03 A.M. The running schedule for this trip is shown in Table 
XXVIII. 

Test No. 12. — Upon arriving at the Muncie car shop on the 
return trip of Test No. 11, the trailer was dropped. Car "284" 
was then run into Muncie and Test No. 12 was made without the 
trailer. The car left Muncie on this test at 3.05 p.m. The run- 
ning schedule is given in Table XXIX, 



SERVICE TESTS OF AM INTERURBAN CAR 157 

Upon returning to Anderson from Muncie at the end of 
Test No. 12, the trailer was again attached to car "284" at the 
Muncie shops. The cars were then taken to the Anderson shops 
where they arrived at 9.30 p.m. 

It will be seen from the above outline of the tests that besides 
showing the general condition of operation of interurban cars in 
service, they make possible a comparison of the performance of 
an interurban car when operated alone and when hauling a trailer 
over the same route and on the same schedule. 

ORIGINAL MEASUREMENTS. 

The original data obtained in the service tests on car "284" 
may be divided into three classes: 

(a) Data relating to electrical input. 

(h) Data relating to speed and distance. 

(c) Data relating to the temperature of the motors. 
In preparing for the tests upon the interurban car it was 
decided to record all of the measurements graphically, the ex- 
perience gained in the early tests being utilized in perfecting the 
recording apparatus. In view of the time and expense involved, 
it was considered impracticable to secure additional instruments 
similar to the General Electric Company's recording ammeter, 
which is entirely automatic in its action. It was necessary, 
therefore, to design simple but effective recording devices which 
could be quickly and cheaply constructed. 

Recording Apparatus. 

The experience with the automatic speed recording device 
used at St. Louis, was so satisfactory that it was decided to use 
the same principle in the construction of a more elaborate appa- 
ratus, correcting such defects as the operation of the instrument 
had brought to light. The original suggestion for this manual 
recording device came from Prof. H. J. Ryan, of Cornell Univer- 
sity, who had worked out the details of the plan some years ago, 
and had used it in connection with thesis work. The general prin- 
ciple is similar to that employed by Mr. J. D. Keiley in tests made 



158 ELECTRIC RAILWAY TEST COMMISSION 

for the New York Central Railroad.* The same idea has been 
employed on a much more elaborate scale on the car test re- 
corder of the Boston Elevated Railway Company.^ 

The total current in conjunction with other values was 
manually recorded on the general graphical record, and as the 
recording ammeter of the General Electrical Company was also 
employed in these tests, as in all the other service tests, to record 
the total current taken by the car, a check upon the accuracy 
and delicacy of the manually operated recorder was obtained. 

A general view of the apparatus is shown in Fig. 48, while in 
Fig. 49 is given a detailed drawing of it. In general, the appa- 
ratus consists of a strip of paper drawn over a table by means of 
a motor. Across this paper move recording pens which are 
operated by cords passing around drums mounted over the 
centers of the various instruments. 

The record paper, which was a strip of manila paper of good 
quality and about 24 in. in width, was contained upon a reel 
placed at one end of a table. This table was 6 ft. in length and 
3 J ft. in width, outside dimensions. The paper was drawn from 
one end of the table to the other over an elevated section, and 
coiled upon a reel at the other end after the records had been 
made. The driving force was a spring motor, S, by which was 
driven a pair of rubber covered wooden rollers. The paper was 
drawn over the table by these rollers, and was guided by raised 
strips along the edge of the center portion of the table. The 
paper was kept taut by being drawn through a pair of friction 
rollers near the supply reel. The reel for the complete record 
was operated by hand, which plan was found very satisfactory. 
It was originally intended to drive this reel by a small motor, 
allowing the driving belt to slip when the slack had been taken 
up, but the plan mentioned above was found to be simpler and 
more effective. 

^ See article on ''Train Testing," by Sydne}'- W. Ashe, Street Railway 
Journal, Volume XXIII, page 768, 

2 See article on "Car Test Recording," of Boston Elevated Railway Com- 
pany. J. M. Ayer and H. S. Knowlson, Street Railway Journal, Volume 
XXVI, page 68. 



SERVICE TESTS OF AN INTERURBAN CAR 



159 



"fa" 

00 



5j 



5' 




160 



ELECTRIC RAILWAY TEST COMMISSION 



Over the paper was mounted, at right angles to its direction 
of motion, six round brass rods, R, R, etc. To these were 
clamped the time marking devices, M, M, etc. These magnets 
were provided with armatures mounted upon hinged arms and 
carrying recording pens made of glass tubing drawn out to 
points. It was convenient for this purpose to use the relays 
manufactured by the Electric Tabulating Machine Company, 



&-0 



zo^ — 4^ IS"— 4 



le" 



■^ 



•15^ 



3" 



--X 





M, 



jyt3Ji^''**-/\'^ '1 '>'>'^J>^yjLf_p ooi^-/y'>oi>ii'2^'p<s-^ez'"*yy 




n @ m cai r-^^-i 

Fig. 49. — Diagram of Recording Apparatus used in Inter urban Car Test. 



for use in their electric tabulating machines. These pens 
marked the base lines for the various records. They were all 
connected in series and in series also with the time marking de- 
vice of the General Electric recording ammeter, and all of the 
magnets were thus energized once every five seconds. When 
energized in this manner, each pen made a mark upon the base 
line corresponding to the impulse received. Upon the record 
sheet were synchronized all of the records made by this means. 



SERVICE TESTS OF AN INTERURBAN CAR 161 

Upon the rods, R, R, were also mounted sliding pen carriages 
for making the various records. These pen carriages were at- 
tached to points on the endless cords, B, B, which passed over 
drums, D, D, carried upon the instrument cases and over ten- 
sion pulleys, P, P, clamped to the rods. For the cords, well- 
stretched fish lines of good quality were foimd to be entirely 
satisfactory. The tension pulleys consisted of small brass 
pulleys mounted upon springs, which were in turn attached to 
brass clamps. A wooden drum with grooved circumference, 
3 inches in diameter, was mounted with its center over the case 
of each electrical instrument. From this drum projected a 
pointer so that the movements of the needle of the instrument 
could be followed by rotating the drimi. A handle attached to 
each drum increased the convenience of operation. Operators, 
seated three on each side of the table, followed with the pointers 
of the several instruments the defl3ctions of the needles, trans- 
mitting the motion of the pointer to the sliding pen carriage by 
means of the drimi belt. The extra magnet, M, was a marking 
device used for the purpose of recording the time of passing cer- 
tain poles. The apparatus as described was self-contained and 
portable, so that it could readily be set up in the car, or moved 
from car to car if necessary. 

As stated in Chapter I, the car tested had two general compart- 
ments. The recording apparatus was placed transversely in this 
compartment, one end being opposite to the third window from 
the front of the car on the left-hand side. The recording table 
was separated from its supporting table by thick felt blocks, and 
the table legs were cushioned by means of felt pads. These pre- 
cautions were taken in order to reduce as much as possible the 
shock and jar incident to the movement of the car. A second 
table was placed in the forward end of the compartment, and upon 
this table were placed the General Electric recording ammeter, 
and two watt-hour meters, which latter were placed in the main 
line circuit and in the motor-compressor circuit respectively. 
The method of cushioning used for the general recording table 
was also employed here. 



162 



ELECTRIC RAILWAY TEST COMMISSION 



Diagram of Connections, 

The general diagram of connections for the service tests Nos. 
9, 10, 11, and 12 is given in Fig. 50. 

As seen from this diagram, the main current ran through the 
General Electric recording ammeter and the watt-hour meter, 
showing the total energy. Other current data, such as the total 
car current and the current in the various motors, was obtained 
by means of Weston milli- voltmeters connected to shunts placed 
in the car wiring circuits. The shunt for the total car current 
was placed on the table with the recording ammeter and watt- 



CANOPi Switch 




Fig. 50. — Diagram of Connections, Inter urban Car Servia Teste. 



hour meters. The shunts for the various motors were connected 
directly in series in the car wiring circuits at the motor terminal. 
This was done by disconnecting the bayonet connections and 
inserting the shunts, which latter had been previously provided 
with short leads with bayonet terminals. 

Pressure wires, consisting of No. 14 B & S gage rubber-cov- 
ered copper wire, were run from the shunts to a terminal board 
which was placed directly under the recording apparatus. The 
pressure wires ended at binding posts on the terminal board, 
from which connections were made directly to the instruments 



SERVICE TESTS OF AN INTERURBAN CAR 163 

which produced the general record. Pressure wires from the 
motor terminals were also brought to this terminal board and 
connected with the instruments as desired. 

All wiring from the motors to the terminal board was run on 
porcelain insulators on the underside of the car body to a point 
directly below the third w^indow on the left-hand side of the car. 
From this point it was run up on porcelain insulators mounted 
on wooden strips fastened to the side of the car, passed through 
the car window and then down to the terminal board. By this 
arrangement, it was not necessary to bore any holes through the 
car floor, which would have been objectionable. 

Because of the weather conditions, it was necessary to keep all 
windows closed. A false sash was put in at the lower edge of 
the window and the window raised slightly, the wiring running 
through porcelain tubes inserted in the false sash. 

As it was irapossible to take more than six records on the gen- 
eral apparatus at any one time, it became necessary to arrange 
connections so that additional records could be taken at differ- 
ent times on certain of these instruments. One voltmeter was 
arranged with four sets of mercury cups so that the pressure 
across the brushes of any one of the four motors could be read. 
In a similar manner two ammeters were arranged with double 
pole, double throw switches so that the current in any two motors 
could be obtained at the same time. 

Speed and Distance Measurements. 

A graphical record of the speed throughout the entire test was 
obtained by means of an "Apple" ignition generator driven by 
the car axle, the speed of which was shown by the reading on the 
milli-voltmeter, which reading was recorded by means of the 
general recording apparatus. As in the tests on the single-truck 
city car, the field current for this small generator w^as supplied 
from a storage battery which also supplied the current for the 
movable coil of the recording ammeter. A constant current of 
one ampere was sent through both of these devices in series. In- 
stead of using a belt to connect the speed generator to the car 



164 



ELECTRIC RAILWAY TEST COMMISSION 



axle, a sprocket chain and gears were employed for this purpose. 
This method of connecting was the natural outgrowth of the ex- 
perience obtained in the service tests on the other two cars. Diffi- 
culty was experienced at first in keeping the sprocket chain on the 
gears, but this difficulty was overcome by the use of flanges on 
both sprockets. The sprockets of an ordinary bicycle were used 
in this connection with the corresponding bicycle chain. The 




Fig. 51. — " Apple " Generator Attached to the Car Axle. 



arrangement of the small magneto-generator relative to the truck 
is shown in Fig. 51. 

In addition to the general speed record as made by means of 
the small generator, an electro-magnet was placed on the record- 
ing apparatus and connected to a battery circuit through a push 
button. This push button was operated by an observer seated 
in the front vestibule, and a record was made in this way at the 
instant the front vestibule of the car passed every fifth pole. 



SERVICE TESTS OF AN INTERURBAN CAR 



165 



Every fifth pole has its number painted on the pole, and these 
numbers were placed on the general record sheet. By this means 
an absolute record of the position of the car at a given time was 
obtained on the general record sheet. In addition to these 
records, an observer seated in the front vestibule recorded on a 
separate log sheet the time of passing street intersections in 
cities, sidings, and towns, and also the pole number at frequent 
intervals. 

Electrical Measurements. 



Quantity Measured. 



Line pressure 

Total current 
Total current 

Total energy- 



Energy taken by motor 
compressor. 



Individual motor cur- 
rents. 

Individual motor pres- 
sures. 

Resistances of motor 
fields. 



Resistances of motor ar- 
matures. 



Instrument 
Employed. 



Weston indicating volt- 
meter. 

General Electric record- 
ing ammeter. 

Weston milli-voltmeter 
with shunt. 

General Electric watt- 
hour meter. 



Duncan watt-hour me- 
ter. 



Weston milli-voltmeters 
with shunts. 

Weston voltmeters. 



Weston ammeter and 
milli-voltmeter. 



Weston ammeter and 
milli-voltmeter. 



Method of Making 
Measurements. 



Continuous record on 
general record appar- 
atus. 

Continuous record for 
entire tests. 

Continuous record by 
general recording ap- 
paratus. 

Readings recorded at 
ends of runs and at 
intervals of approxi- 
mately 30 minutes. 

Readings recorded at 
ends of runs and at 
intervals of approxi- 
mately 30 minutes. 

Readings recorded at 
intervals throughout 
the test. 

Readings recorded at 
intervals throughout 
the tests. 

Resistances measured 
periodically through- 
out the tests and the 
temperatures deduced 
therefrom. 

Resistances measured at 
the beginning of the 
test and at Muncie, 
Anderson, and Indian- 
apolis. The rise in 
temperature of the 
motor armatures was 
deduced from these 
measurements. 



166 ELECTRIC RAILWAY TEST COMMISSION 

Temperature Measurements. 

The temperature measurements included the determination 
of the electrical resistances of the armatures of the motors at the 
beginning and end of each test, and at Muncie and Indianapolis. 
These readings were obtained by means of Weston ammeters 
and milli-voltmeters in conjunction with a storage battery. The 
general method was similar to that employed in the other service 
tests on electric cars. Besides these measurements the resist- 
ances of the fields of the motors were taken at frequent intervals 
throughout the tests by means of Weston ammeters and milli- 
voltmeters, as explained above. From these various electrical 
readings of resistances, the temperature of the armatures and of 
the fields of the various motors was obtained for various periods 
of the day. 

In addition to these electrical measurements of temperature, 
readings were made by means of thermometers of the tempera- 
ture of the air throughout the tests and the temperatures of the 
commutator, and of the air gap surfaces of the motors at the 
beginning and end of the tests and at Indianapolis and Muncie 
stops. 

Sundry Measurements. 

Other data taken in connection with the service tests of the 
interurban car, relate to the condition of the weather, the number 
and duration of the applications of compressed air in braking, 
the number and duration of the applications of the controller, 
the number of times the whistle was used, the time of passing 
sidings, and other similar data. The various measurements 
recorded and covering the acceleration and braking of the car will 
be considered more fully in connection with Parts III and IV, 
which relate specifically to these operations. 

Working up the Results. 

The methods used in working up the results will now be 
considered. 

The records were carefully worked over, and the various stops 
were indicated and synchronized between the different sources 



SERVICE TESTS OF AN INTERURBAN CAR 



167 



of information. The city limits of Muncie, Anderson, and In- 
dianapolis were recorded as were also the various towns and 
sidings between cities. This was done both for the recording 
ammeter record and the general record. The recording ammeter 
record was then integrated, and the average current obtained 
between various points throughout the tests. These points in 
general have been taken at the terminal stations in Muncie, 
Anderson, and Indianapolis, at the limits of these cities, and at 
the towns along the way. The average current and the time 
taken in traversing the distance were obtained in each case. 

The ammeter record on the general record sheet was next 
worked up, and the average current found as in the preceding 
case. The various stops were checked with those on the record- 
ing ammeter record. In a similar manner, the pressure record 
was averaged between the various stops. From these data the 
average power, the duration of run, and the watt-hours were 
obtained for the various portions of the trip. These data are 
shown in Tables XIV to XXV inclusive. 

From the following recorded data, it will be seen that the cur- 
rent record, as obtained by means of the indicating ammeter and 
general recording device, agrees very fairly well with the record 
made by the General Electric recording ammeter, which is en- 
tirely automatic in its action. That a personal error does exist 
in the manipulation of this instrument, however, is shown by 
the fact that it is sometimes high and sometimes low in com- 
parison with the Ganeral Electric recording ammeter, while in 
general it is low. 

The distances between the various stops were accurately de- 
termined from the general operating train schedule sheet of the 
company, and from pole data obtained during the tests. The 
tim.e of run between the various stops was obtained directly 
from the general records, as was also the time of stop, and the 
lay-over at cities and sidings. Knowing the distances traversed 
and the time of run, the average speeds between the turning 
points were obtained. The stops per mile were obtained from 
the general records. Between cities, these stops were in general 



168 



ELECTRIC RAILWAY TEST COMMISSION 



Table XIV. — Intermediate Results of Test No. 9. 

Limits to Indianapolis. 



Feb. 2, 1905. Muncie Citij 



From 



Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 



To 



Yorktown . 
Daleville . . 
Chesterfield 
Anderson ^ . 
Anderson . . 
Anderson ^ . 
Pendleton . 
Ingalls .... 
Fortville . . 
McCordsville 
Oaklandon . 
Lawrence . . 
Indianapolis 
Indianapolis 



Time, 


Volts, 


Min- 


Aver- 


utes. 


age 


7.33 


516 


8.42 


436 


3.25 


518 


5.75 


490 


4.25 


457 


5.92 


511 


9.75 


427 


7.92 


412 


3.83 


510 


6.33 


440 


3.08 


450 


5. -83 


519 


9.5 


505 


20.67 


422 



Recording Ammeter. Weston Ammeter 



Am- 
peres 
Aver- 
age. 



265 
292 
319 
273 
187 
292 
222 
269 
248 
276 
254 
283 
260 
100 



Watts 
Aver- 
age. 



136,700 
127,300 
165,300 
133,800 

85,500 
149,000 

94,850 
111,000 
126,500 
121,500 
114,300 
147,000 
131,300 

42,000 



Watt- 
Hours. 



16,700 

17,880 

8,940 
12,720 

6,050 
14,700 
15,400 
14,650 

8,070 
12,820 

5,880 
14,280 
20,800 
14,490 



Am- 
peres 
Aver- 
age. 



248 
268 
296 
252 
175 
291 
221 
256 
220 
264 
237 
285 
244 
85 



Watts 

Aver- 
age. 



112,800 
116,800 
153,500 
123,500 

80,000 
148,500 

94,500 
105,500 
112,300 
116,200 
106,700 
148,000 
123,250 

35,830 



Watt- 
Hours. 



13,780 
16,400 

8,310 
11,740 

5,660 
14,640 
15,370 
13,925 

7,170 
12,250 

5,480 
14,370 
19,500 
12,370 



Table XV. 



^ City limits. 

Intermediate Results of Test iVo. 9. Feb. 2, 1905. Indianapolis to 
Anderson. 





To 


Time, 

Min- 
utes. 


Volts, 
Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 

Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Indianapolis 
Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 

Fortville 

Ingalls 

Pendleton . . 
Anderson ^ . . 


Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville .... 

Ingalls 

Pendleton . . 
Anderson ^ . . 
Anderson . . . 


19.0 

13.5 
6.75 
3.083 
6.5 
4.67 
7.83 

13.59 
8.50 


411 
435 
511 
460 
452 
494 
489 
365 
474 


126 
268 
328 
273 
284 
258 
212 
250 
140 


51,800 
116,500 
167,500 
125,500 
128,400 
127,500 
103,700 
92,000 
70,300 


16,400 
26,220 
18,850 

6,460 
13,910 

9,950 
13,530 
20,820 

9,425 


126 
270 
311 
280 
248 
256 
214 
253 
170 


51,800 
117,500 
159,000 
124,200 
112,000 
126,500 
104,600 
93,100 
85,000 


16,400 
26,400 
17,900 

6,385 
12,130 

9,870 
13,660 
21,085 
11,400 



City limits. 



Table XVI. — Intermediate Results of Test No. 9. Feb. 2, 1905. Summary of 

Tables XIV and XV. 





To 


Time, 
Min- 
utes. 


Volts, 

Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie ^ . . , . 
Indianapolis 


Indianapolis 
Anderson . . . 


101.83 

83.42 


462 
439 


231 
220 


106,700 
85,689 


183,380 
135,565 


217 
224 


100,250 

85,478 


170,965 
135,230 



City limits. 



SERVICE TESTS OF AN INTERURBAN CAR 169 



Table XVII. — Intermediate Results of Test No. 10. Feb. 3, 1905. Muncie to 

Indianapolis. 





To 


Time, 
Min- 
utes. 


Volts, 
Aver- 
age 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie 

Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 


Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ''■ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 
Indianapolis 


10.25 
7.25 
7.25 
2.83 
5.67 
2.83 
7.17 
9.83 

11.97 
5.33 
6.83 
3.33 
5.5 

12.08 

17.42 


490 

487 
471 
521 
480 
480 
486 
443 
406 
545 
478 
458 
518 
491 
431 


121 

272 
276 
252 
248 
226 
266 
237 
212 
210 
280 
289 
226 
193 
83 


59,300 
132,.500 
130,000 
131,100 
119,000 
108,480 
129,270 
105,000 

86,000 
114,.500 
133,800 
132,300 
117,000 

94,800 

35,700 


10,120 
16,020 
15,700 

6,180 
11,230 

5,117 
15,448 
17,220 
17,070 
10,170 
15,240 

7,340 
10,670 
19,100 
10,370 


153 
269 
279 
253 
239 
226 
259 
241 
195 
198 
250 
279 
230 
204 
84 


75,000 
131,000 
131,250 
131,800 
114,700 
108,480 
125,870 
106,700 

79,100 
108,000 
119,500 
127,700 
119,000 
100,150 

36,200 


12,810 
15,830 
15,870 

6,225 
10,825 

5,117 
15,051 
17,500 
15,690 

9,590 
13,620 

7,085 
10,850 
20,170 
10,520 



Table XVIII. 



^ City limits. 

Intermediate Results of Test No. 10. Feb. 3, 1905. 
to Muncie. 



Indianapolis 





To 


Time, 
Min- 
utes. 


Volts, 
Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Indianapolis 
Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
P'ortville .... 

Ingalls 

Pendleton . . . 
Anderson ^ . . 


Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville . . . 

Ingalls 

Pendleton . . 
Anderson ^ . . 
Anderson . . . 


16.42 

13.50 

5.75 

4.25 

7.58 
5.17 
8.67 
11.58 
9.50 


406 
464 
547 
491 
470 
520 
498 
405 
374 


105 
294 
210 
241 
264 
212 
190 
243 
167 


42,650 

136,500 

114,800 

118,200 

124,000 

112,500 

94,600 

98,400 

62,500 


11,620 
30,720 
11,020 

8,370 
15,670 

9,690 
13,650 
19,000 
10,000 


94 
270 
250 
239 
249 
217 
210 
234 
168 


38,100 
125,400 
136,500 
117,300 

47,000 
112,800 
104,500 

94,700 

62,800 


10,400 
28,210 
13,110 

8,300 
14,800 

9,715 
15,100 
18,280 
10,050 



Table XIX. 



^ City limits. 

Intermediate Results of Test No. 10. Feb. 
Tables XVII and XVIII. 



3, 1905. Summary of 





To 


Time, 
Min- 
utes. 


Volts, 

Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 

Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie 

Indianapolis 


Indianapolis 
Anderson . . . 


115.5 

82.42 


470 
449 


207 
291 


94,470 
94,600 


187,000 
129,700 


214 
203 


94,000 
93,100 


186,745 
127,970 



170 



ELECTRIC RAILWAY TEST COMMISSION 



Table XX. — Intermediate Results of Test No. 11. Feb. 4, 1905. Muncie 

to Indianapolis. 





To 


Time, 
Min- 
utes. 


Volts, 
Aver- 
age 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie 

Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 


Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 
Indianapolis 


13.67 

7.58 

8.25 

4.00 

6.17 

4.17 

8.00 

10.83 

10.58 

4.58 

7.41 

3.00 

6.91 

14.1 

16.75 


456 
503 
483 
532 
507 
542 
496 
443 
350 
547 
453 
478 
498 
497 
415 


153 
316 
321 
305 
287 
170 
256 
285 
273 
306 
296 
223 
285 
255 
153 


69,800 
159,000 
155,000 
162,300 
144,500 

92,100 
127,000 
126,300 

95,500 
167,000 
134,000 
106,500 
142,000 
126,700 

63,500 


15,900 
20,100 
21,300 
10,830 
14,860 

6,400 
16,940 
22,800 
16,820 
12,800 
16,550 

5,320 
16,320 
29,800 
17,700 


143 

312 
333 
311 
290 
161 
266 
287 
257 
290 
295 
221 
286 
251 
151 


65,200 
156,900 
160,800 
165,400 

14,690 

87,250 
127,200 
131,900 

90,000 
158,600 
133,600 
105,600 
142,400 
124,700 

62,700 


14,850 
19,800 
22,100 
11,000 
15,100 

6,070 
16,990 
23,800 
15,850 
12,150 
16,500 

5,280 
16,375 
29,300 
17,500 



^ City limits. 

Table XXI. — Intermediate Results of Test No. 11. 

to Muncie. 



Feb. 4, 1905. Indianapolis 





To 


Time, 
Min- 
utes. 


Volts, 
Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Indianapolis 
Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville . . . 

Ingalls 

Pendleton . . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Chesterfield . 
Daleville . . . 
Yorktown . . 
Muncie ^ . . . . 


Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville . . . 

Ingalls 

Pendleton . . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Chesterfield . 
Daleville . . . 
Yorktown . . 
Muncie ^ . . . . 
Muncie 


17.17 
14.92 
7.91 
4.0 
7.6 
5.83 
8.75 
11.33 
7.83 
3.83 
7.92 
3.91 
8.42 
9.67 
8.17 


425 
453 
518 
445 
432 
497 
465 
405 
490 
507 
478 
503 
481 
440 
490 


188 
337 
268 
311 
317 
290 
237 
306 
288 
160 
342 
347 
316 
320 
220 


79,900 
152,600 
137,200 
138,300 
137,000 
144,000 
110,200 
124,000 
141,000 

81,000 
163,500 
174,500 
152,000 
140,800 
107,800 


22,850 
37,900 
18,090 

9,200 
17,350 
14,000 
16,000 
23,400 
18,400 

5,200 
21,600 
11,350 
21,300 
22,700 
14,700 


171 
340 
263 
312 
302 
280 
254 
305 
277 
151 
340 
330 
308 
314 
212 


72,700 
154,000 
134,600 
138,800 
130,450 
139,150 
118,100 
123,500 
135,700 

76,550 
162,500 
166,000 
148,150 
138,150 
103,900 


20,800 
38,300 
17,740 

9,250 
16,500 
13,500 
17,200 
23,350 
17,700 

4,900 
21,450 
10,800 
20,800 
22,250 
14,150 



^ City limits. 

Table XXII. — Intermediate Results of Test No. 11. 

Tables XX and XXI. 



Feb. 4, 1905. Summary of 





To 


Time, 

Min- 
utes. 


Volts, 
Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 

Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie ..... 
Indianapolis 


Indianapolis 
Muncie 


126.01 
127 . 26 


466 
462 


249 
281 


113,500 
129,700 


245,340 
274,040 


244 
275 


113,700 
127,000 


240,855 
268,690 



SERVICE TESTS OF AN INTERURBAN CAR 



171 



Table XXIII. — Intermediate Results of Test A'o. 12. 

Indianapolis. 



Feb. 4, 1905. Muncie to 





To 


Time, 
Min- 
utes. 


Volts, 
Aver- 
age 


Recording Ammeter. 


Weston Ammeter, 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie 

Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 


Muncie ^ . . . . 
Yorktown . . 
Daleville . . . 
Chesterfield . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Pendleton . . 

Ingalls 

Fortville . . . 
McCordsville 
Oaklandon . . 
Lawrence . . . 
Indianapolis ^ 
Indianapolis 


8.00 
7.08 
7.00 
3.17 
5.25 
4.75 
6.75 
10.08 
8.67 
4.50 
6.58 
3.42 
5.17 
10.58 
16.00 


454 
494 
460 
487 
468 
501 
450 
467 
412 
492 
447 
431 
512 
474 
357 


145 
249 
278 
300 
232 
107 
233 
190 
227 
221 
240 
299 
208 
290 
112 


65,920 
123,000 
128,000 
146,100 
108,500 

53,600 
105,000 

88,730 

92,500 
108,900 
107,200 
129,000 
106,500 
137,800 

39,980 


8,790 

14,550 

14,980 

8,110 

9,500 

4,230 

12,780 

14,900 

13,480 

8,160 

11,750 

7,350 

9,180 

24,300 

10,670 


132 
237 
263 
274 
239 
102 
221 
189 
224 
224 
230 
283 
191 
255 
109 


59,850 

117,070 

121,000 

133,400 

112,000 

51,100 

99,600 

88,250 

92,200 

110,000 

102,800 

122,000 

97,800 

120,800 

38,900 


7,970 

13,850 

14,150 

7,400 

9,800 

4,040 

12,080 

14,820 

13,300 

8,260 

11,250 

6,950 

8,420 

21,300 

10,380 



^ City limits. 

Table XXIV. — Intermediate Results of Test No. 12. 

to Muncie. 



Feb. 4, 1905. Indianapolis 





To 


Time, 

Min- 
utes. 


Volts, 

Aver- 
age. 


Recording Ammeter. 


Weston Ammeter. 


From 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 

Aver- 
age. 


Watt- 
Hours. 


Indianapolis 
Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville . . . 

Ingalls 

Pendleton . . 
Anderson ^ . . 
Anderson . . . 
Anderson ^ . . 
Chesterfield . 
Daleville . . . 
Yorktown . . 
Muncie ^ . . . . 


Indianapolis ^ 
Lawrence . . . 
Oaklandon . . 
McCordsville 
Fortville . . . 

Ingalls 

Pendleton . . 
Anderson '^ . . 
Anderson . . . 
Anderson ^ . . 
Chesterfield . 
Daleville . . . 
Yorktown . . 
Muncie ^ . . . . 
Muncie 


17.33 

13.58 

5.17 

3.42 

7.66 

6.42 

10.75 

10 . 25 

8.67 

4.17 

6.00 

3.25 

6.92 

7.33 

8.5 


395 

425 
497 
434 
444 
484 
418 
393 
490 
502 
496 
434 
498 
470 
487 


107 
301 
246 
279 
241 
219 
179 
254 
189 
143 
309 
280 
263 
282 
132 


42,300 

128,100 

122,250 

121,000 

107,000 

106,000 

74,800 

99,800 

92,600 

71,700 

153,260 

121,500 

130,950 

132,500 

64,300 


12,230 
29,000 
10,525 

6,900 
13,650 
11,350 
13,400 
16,900 
13,400 

4,980 
15,325 

6,570 
15,050 
16,150 

9,130 


105 
270 
208 
217 
221 
191 
158 
237 
189 
133 
290 
275 
243 
260 
132 


41,500 

114,900 

103,370 

94,200 

98,300 

92,400 

66,200 

93,100 

92,600 

67,000 

143,840 

119,500 

121,000 

122,200 

64,300 


12,000 
26,000 

8,900 

5,360 
12,530 

9,890 
11,850 
15,830 
13,400 

4,660 
14,380 

6,460 
13,900 
14,900 

9,130 



^ City limits. 

Table XXV. — Intermediate Results of Test No. 12. Feb. 4, 1905. Summary of 

Tables XXIII and XXIV. 





To 


Time, 
Min- 
utes. 


Volts, 

Aver- 
age. 


Recording Ammeter. 


Weston Ammeter, 


From 


Am- 
peres 

Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Am- 
peres 
Aver- 
age. 


Watts 
Aver- 
age. 


Watt- 
Hours. 


Muncie 

Indianapolis 


Indianapolis 
Muncie 


107.00 
119.42 


480 
447 


210 
217 


97,000 
97,600 


172,730 
194,560 


195 
199 


92,000 
90,100 


163,970 
179,190 



172 ELECTRIC RAILWAY TEST COMMISSION 

only at towns or at sidings where trains were passed. In the 
cities of Muncie, Anderson, and IndianapoUs, however, it was 
necessary to make a number of stops. These stops were re- 
corded on the general record sheet, and it will be noted that the 
stops per mile in cities is considerably greater than between 
cities. The equivalent passenger load has been taken as thirty 
passengers, as explained above under the general heading " Total 
Weight of the Car." 

The total watt-hours between stops was obtained, as stated 
above, by mul iplying together the average pressure, the aver- 
age current (as obtained from the recording ammeter data), and 
the time of run. This method of obtaining the average power 
is not as accurate as would be that of plotting a watt curve 
from the instantaneous values of the current and pressure, and 
integrating this curve. However, it was considered to be im- 
practicable to go to this additional refinement, as the limited 
time available would not permit of doing so. 

The watt-hours per car-mile were obtained by dividing the 
total watt-hours in each case by the number of miles between 
the points considered. The energy in watt-hours per ton-mile 
was obtained by dividing the energy in v/att-hours per car-mile 
by the total weight of the car, which was 39.33 tons. In Test 
No. 9, when the trailer was hauled by Car No. "284," the weight 
of the loaded trailer was added, making the total weight 62.16 
tons. The energy in watt-hours per average through passenger 
carried, was obtained by dividing the total energy in watt- 
hours in each case by the equivalent passenger load. In Tests 
Nos. 9, 10, and 12 this number was 30, while in Test No. 11, it 
was increased to 70, because of the trailer load. 

Results of the Tests. 

Some of the more important numerical results of the various 
tests made on the interurban car are shown in tabular form in 
the sjmopsis at the beginning of the chapter. 

It has been found impossible to represent the results of all 
of the tests graphically, and the more detailed data for each of 



SERVICE TESTS OF AN INTERURBAN CAR 173 

these tests are shown below in Tables XXVI to XXIX inclusive, 
which are supplemented by log sheets similar to those accom- 
panying the tables of results of the service tests of the double- 
truck city car showTi in Chapter III. In these tables will be 
found the detailed data showing the general results between the 
various stops for each test as well as general summaries of these 
results between cities. The average data for the tests, together 
with other items showing the conditions under which each test 
was run and the final rise in temperature of the motors, will be 
found in the log sheets accompanying the tables. 

THE GRAPHICAL LOG. 

While it has not been considered possible to represent graphi- 
cally the results of the various service tests made upon the 
interurban car, it has been thought desirable to show in such 
a manner the results of a portion of one test, which portion has 
been taken as typical of the conditions existing throughout the 
entire series of the tests. This graphical representation is shown 
in Plate II, Fig. 52. The section chosen for this purpose, which 
was selected more or less at random, is the run from the station 
in Anderson to the town of McCordsville, which lies 21.02 miles 
southeast of Anderson, and is somewhat more than half way to 
IndianapoUs from that city. 

Time has been taken as a base in making up this graphical 
log. The profile is consequently not shown, but will be found 
in Fig. 53. The per cent grade at various points along the line 
is shown, however, on the graphical log. 

The Speed Curve. 

The speed curve was transferred from the general speed record 
in the following manner. Various sections of the original speed 
curve were integrated, and the average ordinates obtained for 
known intervals of time. From the pole record the actual dis- 
tance traversed during this interval was accurately obtained. 
From the distance and time data the average speed was obtained, 
and consequently the speed for a given ordinate could then be 



174 ELECTRIC RAILWAY TEST COMMISSION 

calculated. By proceeding in this way, and taking portions of 
the speed curve, which shows different ordinates, the speed cali- 
bration curve was obtained. The speed curve was directly 
transferred to the graphical log by erecting ordinates at the five- 
second intervals and finding the exact speed at these ordinates 
by means of the calibration curve. 

The Pressure Curve. 

The pressure curve was obtained by transferring the original 
record to the graphical log. In order to do this it was necessary 
to obtain a calibration curve showing the relation between the 
ordinates and the actual voltage values at periods throughout 
the tests. Ordinates were then erected at the five-second points 
on the original curve, and their values obtained by means of the 
calibration curve. These points were then transferred to the 
graphical log and the pressure curve was drawn, the general 
form being taken from the original record. 

The Current Curve. 

The current curve was re-plotted directly from the current 
curve produced by the General Electric recording ammeter, 
which record was already on a time base. The same method of 
procedure was employed in making this transfer as in the case 
of the pressure curve. The General Electric recording ammeter 
ordinates have a value of 200 amperes to the inch in this test. 
The ordinates at the five-second points were therefore measured 
and transferred to the graphical log. 

The Power Curve, 

The power curve was obtained by multiplying together the 
instantaneous values of the line pressure and current curves, 
for each five-second interval throughout the run. These points 
were plotted and intermediate points filled in according to the 
general shape of the current curve, due consideration being given 
to the variations in the pressure curve during the interval. 



KA^ 




4;26 4i26 4:27 4*^8 4:29 4U30 4:31 

(To face page 174) 



\. 




Time p.ro.3:49 3^50 3«1 3:52 3:53 3:54 3^55 3:56 3S7 3:58 3:59 4^00 4:0 4M32 4:03 4r04 4:05 4:06 4X>7 4:08 4t)9 4:10 4:11 4'12 4:13 4:14 4:15 4:16 4^17 4:18 4119 4:20 4:21 4:22 4:23 4:24 425 4:26 4:27 4-^8 4:29 4U30 4:31 

I^LATE li, Fig. 52 — Graphical Log of Run from Anderson to McCordsville. tTo iacepagc 



1 



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Fig. 53 B. — Prufile between Anderr;uii and Indianapolis. 



1 



SERVICE TESTS OF AN INTERURBAN CAR 175 

The Energy Curve. 

The curve showing the total energy consumed up to a certain 
point on the run was obtained by integrating the power curve 
up to this point. No attempt was made to show the variations 
in the form of the energy curve between the points considered, 
and the increase in energy taken is shown by a straight Une from 
one point to the next in each case. 

The Distance Curve. 

The distance curve was obtained directly from the data show- 
ing the time of passing various known points throughout the 
run. 

THE GENERAL LOG ACCOMPANYING THE GRAPHICAL LOG. 

The general log for this particular portion of the line is given 
in considerable detail. It shows the general conditions under 
which this particular portion of the run was made, in a manner 
similar to the explanatory logs accompanying the tabulated gen- 
eral results of the various tests. In this log will be found addi- 
tional data concerning the maximum values of speed and power 
for the specific portion of the run considered. 

In order to show the relations of the maximum values of 
speed, current, and power to the average values, the following 
plan was employed. From the time-speed, time-current, and 
time-power curves, the maximimi values of all loops were ob- 
tained and these maximum values were averaged in each case. 
This gave the average maximum values of the quantities. The 
highest value which each quantity attained during the test was 
also obtained, in order to show the extreme maximum values 
and their relation to the average maximum values. 

GENERAL LOG SHEET OF TEST NO. 9. 

Date, Thursday, February 2d, 1905; Place, Central Indiana; 
Route, Muncie-Anderson-IndianapoUs section of the Indiana 
Union Traction Company's system. This test included the run 
from Muncie city limits to Indianapolis, and from Indianapolis 



176 ELECTRIC RAILWAY TEST COMMISSION 

to Anderson. In addition, the car was run from the Anderson 
shops to Muncie before the test was started, and from Anderson 
to the Anderson shops after the test was completed. 

Weather, clear, no snow. The average air temperature dur- 
ing the run was — 16.4° C. or + 2.5° F. Condition of the track, 
dry and clean. Test started, 11: 23 a.m. Test stopped, 4:40 p.m. 
Total duration of test, 5.29 hours. Equivalent load, 30 passengers. 

Average Data for the Day. 

Pressure Measurements. — (Including all ordinary stops but 
no lay-over.) Line pressure for the test, 451.4 volts; line pres- 
sure in cities, 438.0 volts; hne pressure between cities, 457.6 
volts. 

Distance Measurements. — Total length of run during test, 
93.90 miles; total length of run in cities,^ 12.20 miles; total 
length of run between cities, 81.70 miles; stops for total rim 
during test, 32; stops for the total run in cities, 18; stops for 
total run between cities, 14; stops per mile for the test, 0.34; 
stops per mile in cities, 1.48; stops per mile between cities, 
0.17; average length of run in cities, 0.68 miles; average length 
of run between cities, 5.84 miles. 

Time Measurements. — Total interval of test (including all 
lay-overs), 317.25 minutes; lay-over at Anderson, 5.83 minutes; 
lay-over at Indianapolis, 95.83 minutes; lay-over at Lawrence, 
5 minutes; lay-over at Siding No. 12, 22.59 minutes; lay-over 
at Madison Ave. (Anderson), 2.75 minutes; total interval of 
lay-over, 132.00 minutes; running time for the test (including 
ordinary stops but no lay-over), 185.25 minutes; total running 
time in cities, 58.34 minutes; total running time between cities, 
126.91 minutes; average interval of a single run for the test 
(start to stop), 5.79 minutes; average interval of a single run in 
cities (start to stop), 3.24 minutes; average interval of a single 
run between cities (start to stop), 9.07 minutes. 

Speed Measurements. — (Including all ordinary stops b\.it no 
lay-over). Average speed for the test, 30.41 miles per hour; 

^ Anderson and Indianapolis. 



SERVICE TESTS OF AN INTERURBAN CAR 



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average speed in cities, 12.55 miles per hour; average speed 
between cities, 38.63 miles per hour. 

Ciirrent Measurements. — (Including all ordinary stops but 
no lay-over.) Average current for the test, 220.5 amperes; aver- 
age current in cities, 140.3 amperes; average current between 
cities, 257.5 amperes. 

Power Measurements. — (Including all ordinary stops but no 
lay-over.) Average power for the test, 103,302 watts; average 
power in cities, 62,805 watts; average power between cities, 
12,180 watts. 

Energy Measurements. — (Including all ordinary stops but no 
lay-over.) Total energy for the test, 318,945 watt-hours; total 
energy in cities, 61,065 watt-hours; total energy between cities, 
257,880 watt-hours; energy per car-mile for the test, 3397 watt- 
hours; energy per car-mile in cities, 5005 watt-hours; energy 
per car-mile between cities, 3156 watt-hours; energy per ton- 
mile for the test, 85.6 watt-hours; energy per ton-mile in cities, 
126.2 watt-hours; energy per ton-mile between cities, 79.6 watt- 
hours; energy per average through passenger carried for the 
test, 10,632 watt-hours; energy per average through passenger 
carried in cities, 2036 watt-hours; energy per average through 
passenger carried between cities, 8596 watt-hours. 

GENERAL LOG SHEET OF SERVICE TEST NO. 10. 

Date, Friday, February 3d, 1905; Place, Central Indiana; 
Route, Muncie-Anderson-Indianapolis section of the Indiana 
Union Traction Company's system. This test includes the run 
from Muncie to Indianapolis and from Indianapolis to Ander- 
son. In addition, the car was run from the Anderson shops to 
Muncie before the test was started, and from Anderson to the 
Anderson shops after the test was completed. 

Weather, clear, no snow. The average air temperature during 
the run was —11.4° C. or 11.5° F. Condition of the track, dry 
and clean. Test started, 11:12 a.m. Test stopped, 3:08 p.m. 
Total duration of test, 3.94 hours. Equivalent passenger load, 30 
passengers. 



SERVICE TESTS OF AN INTERURBAN CAR 179 

Average Data for the Day. 

Pressure Measurements. — (Including all ordinary stops but no 
lay-over.) Line pressure for the test, 471.5 volts; line pressure 
in cities, 459.0 volts; line pressure between cities, 434.0 volts. 

Distance Measurements. — Total length of run during test, 
95.02 miles; total length of run in cities, 13.36 miles; total 
length of run between cities, 81.70 miles; stops for total run 
during test, 29; stops for total run in cities, 13; stops for total 
run between cities, 16; stops per mile for test, 0.31; stops per 
mile in cities, 0.97; stops per mile between cities, 0.20; aver- 
age length of run for the test, 3.28 miles; average length of run 
in cities, 1.02 miles; average length of run between cities, 5.10. 

Time Measurements. — Total interval of test (including all 
stops but no lay-over), 236.5 minutes; lay-over at Anderson, 
2.75 minutes; lay-over at Indianapolis, 35.83 minutes; total 
interval of lay-over, 38.58 minutes; rimning time for the test 
(including all ordinary stops but no lay-over), 197.92 minutes; 
total running time in cities, 63.59 minutes; total running time 
between cities, 134.33 minutes; average interval of a single run 
for the test (start to stop), 6.83 minutes; average interval of a 
single run in cities (start to stop), 4.88 minutes; average interval 
of a single run between cities (start to stop), 8.40 minutes. 

Speed Measurements. — (Including all ordinary stops but no 
lay-over.) Average speed for the test, 28.84 miles per hour; 
average speed in cities, 12.58 miles per hour; average speed 
between cities, 36.50 miles per hour. 

Current Measurements. — (Including all ordinary stops but no 
lay-over.) Average current for the test, 216.6 amperes; average 
current in cities, 134.3 amperes; average current between cities, 
255.2 amperes. 

Power Measurements. — (Including all ordinary stops but no 
lay-over.) Average power for the test, 96,100 watts; average 
power in cities, 59,200 watts; average power between cities, 
113,400 watts. 

Energy Measurements. — (Including all ordinary stops but no 
lay-over.) Total energy for the test, 316,740 watt-hours; total 



180 



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SERVICE TESTS OF AN INTERURBAN CAR 181 

energy in cities, 62,680 watt-hours; total energy between cities, 
254,060 watt-hours ; energy per car-mile for the test, 3340 watt- 
hours; energy per car-mile in cities, 4700 watt-hours; energy 
p3r car-mile between cities, 3210 watt-hours; energy per ton- 
mile for the test, 841.4 watt-hours; energy per ton-mile in cities, 
118.5 watt-hours; energy per ton-mile between cities, 80.9 watt- 
hours; energy per average through passenger carried for the 
test, 10,558 watt-hours; energy per average through passenger 
carried in cities, 2089 watt-hours; energy per average through 
passenger carried between cities, 8469 watt-hours. 

GENERAL LOG SHEET OF SERVICE TEST NO. 11. 

Date, Saturday, February 4th, 1905; Place, Central Indiana; 
Route, Muncie-Anderson-Indianapolis section of the Indiana 
Union Traction Company's system. This test included the run 
from Muncie to Indianapolis and return, trailer No. "302" 
being hauled throughout the test. Car "284" hauling trailer 
No. "302," was run from the Anderson shops to Muncie before 
this was started. 

Weather, clear and cold, no rain. The average air temperature 
during the run was — 8.8° C. or 16.2° F. Condition of the track, 
dry and clean. Test started, 9:03 a.m. Test stopped, 1:52 p.m. 
Total duration of test, 4.81 hours. Equivalent passenger load, 70 
passengers. 

Average Data for the Day. 

Pressure Measurements. — (Including all ordinary stops but no 
lay-over.) Line pressure for the test, 472.5 volts; line pressure 
in cities, 460.0 volts; line pressure between cities, 478.5 volts. 

Distance Measurements. — Total length of run during test, 
113.10 miles; total length of run in cities, 15.22 miles; total 
length of run between cities, 97.88 miles; stops for total run 
during test, 33; stops for total run in cities, 14; stops for total 
run between cities, 19; stops per mile for test, 0.29; stops per 
mile in cities, 0.92; stops per mile between cities, 0.19; average 
length of run for the test, 3.43 miles; average length of run in 



182 



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SERVICE TESTS OF AN INTERURBAN CAR 183 

cities, 1.09 miles; average length of run between cities, 5.15 
miles. 

Time Measurements. — Total interval of test (including all 
ordinary stops but no lay-over), 288.33 minutes; lay-over at 
Anderson, 1.83 minutes; lay-over at Pendleton, 2.00 minutes; 
lay-over at Indianapolis, 22.66 minutes; lay-over at Ingalls, 
3.83 minutes; lay-over at Anderson, 2.08 minutes; lay-over at 
Siding, 11a, 2.66 minutes; total interval of lay-over, 35.06 
minutes ; running time for the test (including all ordinary stops 
but no laj^-over), 253.26 minutes; running time in cities, 79.59 
minutes; running time between cities, 173.67 minutes; aver- 
age interval of a single run for the test (start to stop), 7.68 
minutes; average interval of a single run in cities (start to 
stop), 5.68 minutes; average interval of a single run between 
cities (start to stop), 9.14 minutes. 

Speed Measurements. — (Including all ordinary stops but no 
lay-over.) Average speed for the test, 26.80 miles per hour; 
average speed in cities, 11.45 miles per hour; average speed 
between cities, 33.80 miles per hour. 

Current Measurements. — (Including all ordinary stops but 
no lay-over.) Average current for the test, 265.0 Pvmperes; aver- 
age current in cities, 192.0 amperes; average current between 
cities, 299.0 amperes. 

Power Measurements. — (Including all ordinary stops but no 
lay-over.) Average power for the test, 122,700 watts; average 
power in cities, 89,200 watts; average power between cities, 
138,200 watts. 

Energy Measurements. — (Including all ordinary stops but 
no lay-over.) Total energy for the test, 518,480 watt-hours; 
total energy in cities, 118,090 watt-hours; total energy between 
cities, 400,390 watt-hours; energy per car-mile for the test, 
4580 watt-hours; energy per car-mile in cities, 7770 watt- 
hours; energy per car-mile between cities, 4090 watt-hours; 
energy per ton-mile for the test, 73.8 watt-hours; energy per 
ton-mile in cities, 125.0 watt-hours; energy per ton-mile be- 
tween cities, 65.9 watt-hours; energy per average through pas- 



184 



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SERVICE TESTS OF AN INTERURBAN CAR 185 

senger carried for the test, 7407 watt-hours; energy per aver- 
age through passenger carried in cities, 1687 watt-hours; 
energy per average through passenger carried between cities, 
5720 watt-hours. 

GENERAL LOG SHEET OF SERVICE TEST NO. 12. 

Date, Saturday, February 4th, 1905; Place, Central Indiana; 
Route, Muncie-Anderson-IndianapoHs section of the Indiana 
Union Traction Company's system. This test included the 
run from Muncie to Indianapolis and return to Muncie without 
trailer. Test No. 11 immediately preceded this test, and car 
"284" was run back to the Anderson shops, hauling trailer 
"302," immediately after the close of the test. 

Weather, clear and cold, no snow. The average air tempera- 
ture during the run was — 6.8° C. or 19.8° F. Condition of the 
track, dry and clean. Test started, 3:06 p. m. Test stopped, 
7:50 P.M. Total duration of test, 4.74 hours. Equivalent 
passenger load, 30 passengers. 

Average Data for the Day. 

Pressure Measurements. — (Including all ordinary stops but 
no lay-over.) Line pressure for the test, 449.0 volts; line pres- 
sure in cities, 434.0 volts; line pressure between cities, 473.0 
volts. 

Distance Measurements. — Total length of run during test, 
113.10 miles; total length of run in cities, 15.22 miles; total 
length of run between cities, 97.88 miles; stops for total run 
during test, 27; stops for total nm in cities, 10; stops for total 
run between cities, 17; stops per mile for the test, 0.24; stops 
per mile in cities, 0.66; stops per mile between cities, 0.17; 
average length of run for the test, 4.20 miles; average length 
of run in cities, 1.52 miles; average length of nm between cities, 
5.75 miles. 

Time Measurements, — Total interval of test (including all 
stops but no lay-over), 284.33 minutes; lay-over at Muncie, 5.33 
minutes; lay-over at Anderson, 2.67 minutes; lay-over at 
Siding No, 14, 5.58 minutes; lay-over at Lawrence, 5.75 min- 



186 ELECTRIC RAILWAY TEST COMMISSION 

utes; lay-over at Indianapolis, 27.08 minutes; lay-over at 
Siding No. 27, 3.33 minutes; lay-over at Anderson, 3.17 min- 
utes; lay-over at Siding No. 11a, 5.00 minutes; total inter- 
val of lay-over, 57.91 minutes; running time for the test (in- 
cluding all ordinary stops but no lay-over), 226.42 minutes; 
total running time in cities, 74.17 minutes; total running time 
between cities, 152.25 minutes; average interval of a single 
run for the test (start to stop), 8.39 minutes; average interval 
of a single run in cities (start to stop), 7.41 minutes; average 
interval of a single run between cities (start to stop), 8.79 min- 
utes. 

Speed Measurements. — (Including all ordinary stops but no 
lay-over.) Average speed for the test, 29.95 miles per hour; 
average speed in cities, 12.33 miles per hour; average speed 
between cities, 38.55 miles per hour. 

Current Measurements. — (Including all ordinary stops but 
no lay-over.) Average current for the test, 213.5 amperes; 
average current in cities, 138.5 amperes; average current be- 
tween cities, 250.5 amperes. 

Power Measurements. — (Including all ordinary stops but 
no lay-over.) Average power for the test, 97,300 watts; aver- 
age power in cities, 61,650 watts; average power between cities, 
114,600 watts. 

Energy Measurements. — (Including all ordinary stops but 
no lay-over.) Total energy for the test, 367,290 watt-hours; 
total energy in cities, 76,210 watt-hours; total energy between 
cities, 291,080 watt-hours; energy per car-mile for the test, 
3242 watt-hours; energy per car-mile in cities, 5007 watt- 
hours; energy per car-mile between cities, 2975 watt-hours; 
energy per ton-mile for the test, 81.8 watt-hours; energy per 
ton-mile in cities, 126.1 watt-hours; energy per ton-mile between 
cities, 75.0 watt-hours; energy per average through passenger 
carried for the test, 12,240 watt-hours; energy per average 
through passenger carried in cities, 25,400 watt-hours; energy 
per average through passenger carried between cities, 97,030 
watt-hours. 



SERVICE TESTS OF AN INTERURBAN CAR 187 

GENERAL LOG SHEET FOR GRAPHICAL LOG. PART OF 
SERVICE TEST NO. 12. 
(From Anderson to McCordsville.) 

Date, Saturday, February 4th, 1905; Place, Central Indiana; 
Route, Muncie-Indianapolis section of the Indiana Union Traction 
Company's Unes. The graphical log shows approximately one- 
third of the run from Muncie to Indianapolis, and the part se- 
lected is that from Anderson to McCordsville, a town between 
Anderson and Indianapolis. 

Weather, clear and cold, no rain. The average air tempera- 
ture during the run was — 5.0° C. or 23.0° F. Condition of track, 
drj^ and clean. Graphical log begins at 3:49 p.m. Graphi- 
cal log ends at 4:31 p.m. Total interval shov/n by graphical 
log, 0.7 hours. Equivalent load, 30 passengers. 

Data for the Run. 

Pressure Measurements. — Average line pressure, 435.9 volts; 
miximum line pressure, 575.0 volts; place where maximum 
line pressure occurred at cit}^ limits, Anderson; minimum line 
pressure, 245 volts; place where minimum line pressure occurred, 
leaving Siding No. 14. 

Distance Measurements. — Total length of run, 21.02 miles; 
length of run in Anderson, 2.04 miles ; length of run from 
Anderson city limits to McCordsville, 18.98 nules; stops for the 
total run, 7; stops in Anderson, 3; stops between Anderson city 
limits and McCordsville, 4; stops per mile for total run, 0.31 ; 
stops per mile in Anderson, 1.47; stops per mile between An- 
derson city limits and McCordsville, 0.21; length of a single 
run in Anderson (start to stop), 0.68 miles; length of a single 
run between Anderson city limits and McCordsville (start to 
stop), 3.80 miles. 

Time Measurements. — Interval for total nm (start to stop), 
42.20 minutes; lay-over at Siding No. 14, 5.59 minutes; total 
running time (including ordinary stops), 36.01 minutes; run- 
ning time in Anderson, 6.91 minutes; running time between 
Anderson city limits and McCordsville, 29.5 minutes; average 



188 ELECTRIC RAILWAY TEST COMMISSION 

interval of run in Anderson (start to stop), 2.30 minutes; aver- 
age interval of run between Anderson city limits and McCords- 
ville, 5.87 minutes. 

Speed Measurements. — Average speed between Anderson city 
limits and McCordsville (including all stops), 32.0 miles per hour; 
average speed (including all ordinary stops but no lay-over), 
34.7 miles per hour; average speed in Anderson (including all 
ordinary stops but no lay-over), 17.8 miles per hour ; average 
speed between Anderson city limits and McCordsville (includ- 
ing all ordinary stops but no lay-over), 38.2 miles per hour; 
maximum speed, 56 miles per hour; place where maximum 
speed occurred, north of Fortville. 

Current Measurements. — Average current for the total run 
(including all stops), 205.8 amperes; average current for the 
total run (including all ordinary stops but no lay-over), 237.5 
amperes; average current in Anderson (including all ordinary 
stops but no lay-over), 231.9 amperes; average current between 
Anderson city limits and McCordsville (including all ordinary 
stops but no lay-over), 232.0 amperes; average maximum ciu*- 
rent in Anderson, 603.0 amperes; maximum current in Ander- 
son, 670 amperes; place and time at which maximum current 
occurred in Anderson, after stop at Madison Ave., at 4:20:27 
p. M. ; average maximum current between Anderson city limits 
and McCordsville, 465 amperes; place where maximum current 
occurred, pole No. 1763. 

Power Measurements. — Average power for the entire run 
(including all stops), 88,250 watts; average power for the entire 
run (including all stops but no lay-over), 101,700 watts; average 
power in Anderson (including all ordinary stops but no lay- 
over), 111,500 watts; average power between Anderson and 
McCordsville (including all ordinary stops but no lay-over), 
103,200 watts; average maximum power in Anderson, 251,000 
watts ; maximum power in Anderson, 320,000 watts ; place where 
maximimi power occurred, after stop at Madison Ave.; average 
maximum power between Anderson city limits and McCords- 
ville, 179,500 watts; maximum power between Anderson city 



SERVICE TESTS OF AN INTERURBAN CAR 180 

limits and McCordsville, 300,000 watts ; place and time at which 
maximum current occurred, pole No. 1765, at 4:20:30 p. m. 

Energy Measurements. — Total energy for the entire run, 
61.04 kw. hours; total energy in Anderson, 10.48 K.W. hours; 
total energy between Anderson city limits and McCordsville, 50.56 
kw. hours; energy per car-mile for entire run, 2.90 K.W, hours; 
energ}^ per car-mile in Anderson, 5.13 K.W. hours; energy per 
car-mile between Anderson city limits and McCordsville, 2.66 
kw. hours; energy per ton-mile for entire rim, 73.2 watt-hours; 
energy per ton-mile in Anderson, 129.3 watt-hours; energy 
per ton-mile between Anderson city limits and McCordsville, 
67.1 watt-hours; energy per average through passenger car- 
ried for entire run, 2035 watt-hours; energy per passenger 
carried in Anderson, 349 watt-hours; energy per passenger be- 
tween Anderson city limits and McCordsville, 1685 watt-hours. 

Discussion of Results. 

The service tests on the interurban car give data which may 
be studied from several different standpoints. In the first 
place, they offer information as to the performance of a car 
when run upon a schedule in practical operation on one of the 
larger interurban roads in the Central West, the car being one 
of a number of similar cars used in regular service. In the sec- 
ond place, the data allow of the comparative study of the per- 
formance of the car when operated over a given route and upon 
a given schedule, both with and without a trailer. A compari- 
son of the general data of this chapter with those of Chapters 
II and III also leads to some interesting deductions. 

Tests Nos. 9, 10, 11, and 12 were performed on three consecu- 
tive days, Feb. 2d, 3d, and 4th, 1905, Tests Nos. 11 and 12 
being performed on the latter date. While the data for indi- 
vidual portions of the various tests differ very materially, it is 
interesting to note that the general data for the tests agree very 
closely for the four tests. In this connection, it is to be remem- 
bered that while the same general schedule was adhered to 
throughout all four tests, it was found impracticable to make 



190 ELECTRIC RAILWAY TEST COMMISSION 

Tests Nos. 9 and 10 as complete as were Tests Nos. 11 and 12. 
While it was the intention to run from Mimcie to Indianapolis 
and return in all four tests, it was necessary to cut off Tests Nos. 
9 and 10 at Anderson on the return trip. These two tests, 
therefore, show a run of but 95 miles as against 113 miles for 
Tests Nos. 11 and 12. 

It will be seen that the total duration of the test differed mate- 
rially in Tests Nos. 9 and 10, while Tests Nos. 11 and 12 corre- 
spond very closely in this particular. An inspection of the data 
showing the running time, including all ordinary stops, shows a 
great uniformity in the results obtained for the various tests. 
The discrepancy in the results for the total duration of test is 
accounted for in the time of lay-over, which differed in the 
various tests, although it was nearly the same in Tests Nos. 10 
and 11. The lay-over of more than two hours shown in Test 
No. 9, was caused principally by the great trouble experienced 
with the heating of the journal boxes. 

While it was not considered advisable to rim the car under 
test in regular service, it was run upon the same schedule as 
were the limited cars, and the schedule was so adjusted as not 
to interfere with the operation of the cars in regular service. 
Car No. 284 was loaded with an equivalent passenger load of 
30 passengers and trailer No. 302 with an equivalent passenger 
load of 40 passengers. These loads were considered by the offi- 
cials of the road as representing ordinary practical conditions. 
Tests No. 9, 10, and 12 were with Car No. 284 alone, while in Test 
No. 11 the trailer was hauled by this car. 

An inspection of the data showing the line pressure indicates 
a very considerable variation in this pressure at different periods 
of the test and at certain points on the system. The average 
line pressure for the various tests, however, shows a very fair uni- 
formity, the lowest value being 449 volts in Test No. 12, and the 
highest 472 volts in Test No. 11. A noticeable feature in 
this connection is the fact that the average pressure appears 
to be much lower than would be found desirable for this class of 
service, particularly when it is remembered that the line pres- 



SERVICE TESTS OF AN INTERURBAN CAR 191 

sure often rises to 550 volts or more when no power is taken 
from the system. This not only indicates a considerable loss 
of power in the transmission system, but it also means a reduced 
efficiency of the motors and a decreased speed at the low pre- 
vailing pressures. All of these objections could be remedied 
by the addition of more copper in the feeding system. 

While the current varies largely at different periods of the 
test, and is constantly being turned on and off during the run, 
it is interesting to note how very uniform are the results ob- 
tained for the average current in the various tests. This aver- 
age value is 221 amperes for Test No. 9, 217 for Test No. 10, 265 
for Test No. 11, and 214 for Test No. 12. It is to be observed 
that the average current of Test No. 9 is approximately 3.5 per 
cent higher than that of Test No. 12. This increase m average 
current was undoubtedly due to the increase in friction caused 
by the heating of the journal boxes while Test No. 9 was being 
made. Some difficulty was also experienced in the heating of 
the journal boxes in Test No. 10, and the increase of 3 amperes 
in the average current of this test over that of Test No. 12 may 
be explained in the same way. The average current of Test No. 
11 is approximately 50 amperes more than that for Tests Nos. 10 
and 12. This shows the increase in current necessary for hauling 
the trailer, which was used in Test No. 11. 

As the average line pressure does not differ very materially 
in the four tests, it is to be expected that the average power 
taken will, in general, follow the relative values of the average 
current. This is seen to be the case, the average power for 
Tests Nos. 10 and 12 being almost identical, that for Test No. 9 
being appro ximatety 6 per cent above the power in Tests Nos. 10 
and 12, and that for Test No. 11 (where the trailer was used) 
being approximately 25 per cent greater than for Tests Nos. 10 
and 12. 

The average interval of run in cities differed considerably in 
the four tests, being 0.68 of a mile in Test No. 9, 1.02 miles in 
Test No. 10, 1.09 miles in Test No. 11, and 1.52 miles in Test 
No. 12. This difference is due largely to the difference in operat- 



192 ELECTRIC RAILWAY TEST COMMISSION 

ing conditions in passing through the city of Indianapolis. In 
some runs, it was necessary to make many more stops between 
the city limits and the terminal station than was the case in 
others. The average length of run between cities shows con- 
siderable uniformity, being between 5 and 6 miles in all four 
tests. 

The average speed for the entire test varies between 26.8 
miles an hour in Test No. 11 and 30.4 miles an hour in Test 
No. 9. It is to be observed in this connection that Tests Nos. 9, 
10, and 12 show average speeds which are very close together, 
while Test No. 11 shows an average speed of approximately 
3 miles per hour less than that of Test No. 12. This is due to 
the fact that Car No. 284 was hauling a trailer in Test No. 11, 
and it was impossible to obtain as high speeds with this added 
load as when running alone. The average speed in cities is 
found to be nearly the same for all tests, that of Test No. 11 
being approximately one mile per hour less than for the other 
three tests. The average speed between cities is seen to be 38.5 
miles an hour for Test No. 12, as against 33.8 miles an hour for 
Test No. 11. This shows a loss in speed of 4.7 miles an hour in 
Test No. 11, due to the hauling of the trailer. 

The values showing the kilowatt-hours per car-mile follow in 
general the results giving the average power. Tests Nos. 9, 10, 
and 12 show practically uniform results. Tests Nos. 9 and 10 
having slightly larger values than Test No. 12, due to the fact 
that an increased frictional effect, caused by the heating of the 
journal boxes, was produced in these two tests. The kilowatt- 
hours per car-mile for Test No. 11 are over 40 per cent greater 
than the value shown for Test No. 12. This increase is due to 
the increase in power necessary to haul the trailer. 

The watt-hours per ton-mile were 85.6, 84.4, 73.8, and 81.8 
for Tests Nos. 9, 10, 11, and 12, respectively. The higher values 
of Tests Nos. 9 and 10 were due in part to the increased journal 
friction, especially the value shown in Test No. 9. The value 
shown for Test No. 12, which is 81.8, may be taken as fairly rep- 
resentative of the watt-hours per ton-mile for the interurban 



SERVICE TESTS OF AN INTERURBAN CAR 193 

car alone. Test No. 11, which was with the trailer, shows the 
corresponding value to be 73.8. This gives 8 watt-hours per 
ton-mile as the added energy necessary in hauhng the trailer. 

The watt-hours per equivalent through passenger carried are 
approximately 10,500 in Tests Nos. 9 and 10, 7400 in Test No. 
11, and 12,250 in Test No. 12. It is to be observed that while 
the watt-hours per ton-mile are greater in Tests Nos. 9 and 10 
than in Test No. 12, the watt-hours per equivalent through pas- 
senger carried are considerably less. The reason for this is 
that Tests Nos. 9 and 10 cover a total distance of approximately 
95 miles, whereas Test No. 12 covers a total distance of 113 
miles. The data showing the watt-hours per equivalent through 
passenger for Test No. 11, are to be compared directly with Test 
No. 12, and not with Tests Nos. 9 and 10, as Tests Nos. 11 and 12 
cover the same total distance traversed. It is seen that the 
value showing the watt-hours per equivalent through passenger 
carried is nearly 80 per cent higher for Test No. 12 than for 
Test No. 11. This is for the reason that but 30 passengers 
were carried in Test No. 12, as against 70 passengers in Test 
No. 11, due to the fact that a trailer was hauled in the latter 
test. 

A comparison of the general data obtained for the interurban 
car with the results given in Chapters II and III for the city 
cars, can only be made in a general way. The duration of the 
run was very different in the three tests, as were also the sched- 
ule speed and the stops per mile. While the two city cars had 
an average schedule speed of approximately 10 miles per hour, 
the interurban car had an average schedule speed of nearly 30 
miles an hour, while the maximum speed of the single-truck city 
car was approximately 20 miles an hour and that of the double- 
truck city car was somewhat less than 20 miles an hour, and the 
maximum speed of the interurban car was over 60 miles an hour. 

It is seen from these general considerations, that the average 
power taken by the interurban car would naturally be much 
larger than that taken in the other two cases. This is foimd 
to be the case, as the average power taken by the interurban 



194 ELECTRIC RAILWAY TEST COMMISSION 

car was nearly four times that used by the other two cars, while 
it was nearly five times as much when the interurban car was 
hauling a trailer. With this large increase in power would nec- 
essarily come a corresponding increase in the current drawn 
from the line, if the pressure were the same in the three cases. 
The increase in the current is found to be more than in propor- 
tion, since the average line pressure is less in the interurban tests 
than it is in either of the other two tests. 

The kilowatt-hours per car-mile are approximately 3.3 for 
the interurban car alone, as against 2.7 for the double-truck city 
car, and 2.3 for the single-truck city car. It is seen that these 
results are more nearly comparable than are those relating to 
power and current. The reason for this is that the largely in- 
creased speed of the interurban car very materially reduces the 
time required to traverse a given distance. 

The watt-hours per ton-mile are approximately 83 for the 
interurban car, as against 122 for the double-truck city car, and 
162 for the single-truck city car. It is seen from these data that 
the energy required per ton-mile for the interurban car is con- 
siderably less than for either the double-truck city car or the 
single-truck city car, being but 68 per cent of the former and 
but 51 per cent of the latter. This is due to the largely increased 
weight of the interurban car over the weights of the city cars. 

Data showing the watt-hours per total passenger carried, were 
given in the test on the double-truck city car, whereas the watt- 
hours per equivalent through passenger carried are given in the 
tests on the interurban car. No comparison can be made on 
the basis of passenger carried, for the reason that the conditions 
of service are very different in interurban and in city work. In 
an interurban service such as that existing on the line between 
Mimcie and Indianapolis, the fare charged depends upon the 
distance traversed, whereas in a city service the fare is five cents 
irrespective of the distance traversed. This being the case, a 
comparison on the basis of passengers transported can only be 
made by considering the total number of passengers carried on 
an existing line in a city service, as against the average number 



SERVICE TESTS OF AN INTERURBAN CAR 195 

of through passengers carried on an interurban service. Know- 
ing the rates of tariff for the latter service, it is a comparatively 
simple matter to draw deductions as to the cost of energy sup- 
plied to the car in comparison with the revenue obtained from 
the car. 

The power taken by the air-compressor, incident to the opera- 
tion of the air-brakes and the pneumatic system of control, is 
considered more fully in Chapters VI and IX, where the accel- 
eration and braking tests on the interurban car are considered. 
The control energy was found to be very small indeed, being 
considerably less than one-tenth of one per cent of the total 
energy supplied to the car. 



PART III. 
ACCELEEATION TESTS OF ELECTRIC CARS. 



J97 



CHAPTER V 
ACCELERATION TESTS OF A SINGLE-TRUCK CITY CAR. 



Object of the Tests. 

The principal object of these tests was to bring out the sali- 
ent features of the various factors effecting the acceleration of a 
single-truck city car when the power is turned on by means of 
a manually operated controller, and the car is brought up to a 
given speed in a given distance. It was intended to study 
primarily the maximum current, the maximum power, and the 
energy consumption during the acceleration tests, but the tests 
also included the measurement of such other variables as time, 
current, pressure, speed, and the distances traversed. Five dif- 
erent rates of acceleration were employed, the maximum speed 
attained being the same in each case, and comparisons are made 
in the report of the results obtained under the various con- 
ditions. 

Synopsis of Results. 



Table No. XXX. — Synopsis of Results. 

Truck Car. 



Acceleration. Tests of Single- 



Maximum Speed M.P.H 

Speed at Full Parallel M.P.H. . . 

Time to Attain Maximum Speed 
(Seconds) . 

Time to Attain Full Parallel (Sec- 
onds) . 

Total Distance Traversed (Feet) . 

Distance Traversed to Full Paral- 
lel (Feet) 



Controller Turned to Full Parallel, 



40 Ft. 



20.0 
11.0 
14.5 

4.52 

286.6 
40.0 



199 



70 Ft. 



20.0 
12.4 
16.1 

6.63 

305.5 
70.0 



100 Ft. 



20.0 
13.8 
17.9 

8.88 

322.5 
100.0 



150 Ft. 



20.0 
14.3 
19.1 

11.33 

339.1 
150.0 



200 Ft. 



20.0 
15.3 
21.1 

13.90 

377.2 
200.0 



200 



ELECTRIC RAILWAY TEST COMMISSION 



Table No. XXX. — Continued 



Average Current (Amperes) .... 

Maximum Current at Series Posi- 
tion (Amperes). 

Maximum Current at Parallel Po- 
sition (Amperes). 

Average Power (Kilowatts) 

Maximum Power at Series Posi- 
tion (Watts). 

Maximum Power at Parallel Posi- 
tion (Watts). 

Total Energy (Watt-Hours) 

Average Acceleration I ' — - J . 
Maximum Acceleration 



/ M.H.P. 

[ Sec. 



Controller Turned to Full Parallel. 



40 Ft. 



99.7 
172.0 

298.5 

74.60 
89.4 

149.7 

301.0 
1.33 

2.50 



70 Ft. 


100 Ft. 


150 Ft. 


115.0 
139.6 


122.1 
139.3 


132.2 
135.3 


220.4 


191.2 


158.2 


64.60 
71.6 


62.05 
71.2 


59.75 
70.0 


111.0 


94.2 


80.0 


289.2 


308.3 


317.1 


1.25 


1.12 


1.05 


2.32 


2.32 


2.32 



200 Ft. 



146.7 
115.2 

127.2 

50.60 
59.8 

65.1 

297.0 
0.95 

2.32 



General Conditions of the Tests. 

All of the acceleration tests upon the single-truck car, were 
carried out on the tracks provided for the Electric Railway 
Test Commission by the Louisiana Purchase Exposition Com- 
pany. These tracks were about 1200 feet in length, and were 
located parallel to and directly north of the Transportation 
Building at the St. Louis Exposition. The tests were con- 
ducted on the north one of these tracks, which was tangent and 
level throughout the entire length used. 

The car selected for the acceleration tests was the same single- 
truck car which was used in making the service tests considered 
in Chapter II, and is fully described and illustrated in Chapter 
I. The car equipped and ready for service weighed 24,665 
lbs. and the total weight under the conditions of test was 
28,715 lbs., or approximately 14.3 tons. The load was the 
same as in the service tests of Chapter II. 

As previously stated, the motive power equipment consisted 
of two Westinghouse No. 56 motors, which have a rating of 55 



ACCELERATION TESTS OF A CITY CAR 201 

horse-power each. The controllers were type B 23, and espe- 
cially adapted to the Westmghouse magnet brake apparatus, 
with which the car was equipped. Fig. 54 shows a diagram of 
the connections of the controller and motors for the various 
power notches of the controller. There are sixteen notches on 
a controller of the type used, nine of which are power notches, 
and of these nine, five are for the series connection of the motors 
and four for the parallel connection. The effective utilization 
of the braking notches of the controller is considered in Part 
IV, which treats of the braking tests on this car. 

General Description of the Tests. 

The tests consisted in starting the car from a given point, in 
turning the controller to full parallel in traversing a given dis- 
tance, and in shutting off the power when the car had attained 
a speed of exactly 20 miles an hour. This latter speed was ap- 
proximately the maximum speed which the car would attain 
under the conditions of the tests. The service tests of Chapter 
II show a speed of about 21 miles an hour, but it was consid- 
ered desirable, in making the acceleration tests, to cut off the 
power at' a slightly lower speed than this in order to insure a 
uniform maximum velocity in all rims. 

Five different values of acceleration were employed, the vari- 
ous tests differing only in the manner in which the power was 
turned on. In the five tests the controller was turned to the 
full parallel position in the time interval necessary for the car 
to traverse a distance of 40, 70, 100, 150, and 200 feet respec- 
tively. Twenty rims were taken for each of the five different 
accelerating conditions. Uniform acceleration was obtained in 
each case by practicing starts before any records were taken. 
The criterion for uniform acceleration was freedom from jerks 
in passing from one notch of the controller to the next. The 
motorman was an experienced operator in the employ of the 
Westinghouse Company and, after a few trials, he was able to 
obtain a fairly imiform acceleration under the desired condi- 
tions. 



202 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 13. — In this test tne controller was turned to full 
parallel in 40 ft. The average time taken to cover this distance 
was 4.52 seconds, and a constant speed of 20 miles an hour was 
reached in 14.51 seconds. 

Test No. 14. — In this test the controller was turned to full 
parallel in 70 ft. The average time taken to cover this dis- 

We5tinghou5e La C le.de: Car ., 

T 
5 QEi 




Rzj 




M 



h 







8 ^^y 

9 Q. 



Controller. 
Notch 



^^^^ 



Fig. 54. — Connections of Power Notches of Controller, Single-Trucit City Car. 

tance was 6.63 seconds, and a constant speed of 20 miles an hour 
was reached in 16.1 seconds. 

Test No. 15. — In this test the controller was turned to full 
parallel in 100 ft. The average time taken to cover this dis- 
tance was 8.88 seconds, and a constant speed of 20 miles an hour 
was reached in 17.9 seconds. 



ACCELERATION TESTS OF A CITY CAR 203 

Test No. 16. — In this test the controller was turned to 
full parallel in 150 feet. The average time taken to cover this 
distance was 11.33 seconds, and a constant speed of 20 miles 
an hour was reached in 19.09 seconds. 

Test No. 17. — In this test the controller was turned to 
full parallel in 200 ft. The average time taken to cover this 
distance was 13.90 seconds, and a constant speed of 20 miles 
an hour was reached in 21.09 seconds. 

ORIGINAL MEASUREMENTS. 

The original data obtained in the acceleration tests on the 
single-truck car may be divided into four general classes: (a) 
data relating to electrical input; (b) data relating to time; (c) 
data relating to speed; {d) data relating to distance traversed. 

Electrical Measurements. 

The general method of taking electrical measurements was 
the same as that employed in conducting the service tests on 
the single-truck car, excepting that the readings of the indicat- 
ing instruments were taken at one-second or at two-second in- 
tervals instead of at five-second intervals. It was found by 
trial that one-second intervals were almost too short to take 
readings, and the majority of the data was obtained at two- 
second intervals. The general method of procedure was for 
one person to count the seconds aloud, making use of a stop 
watch, the readings being taken upon the signal. The first 
count was taken as a signal for the start, and all readings were 
recorded for this coimt. The time marker and relay system 
employed in registering the five-second scores on the record- 
ing instruments were also used in these tests. The connec- 
tions of the instruments were in this case made the same 
as in the service tests on this car, and are shown in Fig. 29, 
Chapter II. 

The various electrical measurements are recorded in the fol- 
lowing table : 



204 



ELECTRIC RAILWAY TEST COMMISSION 



Quantity 

Measured. 



Line Pressure, 



Total Current . 
Total Current . 
Motor Currents 



Motor Pressures 



Total Energy . 



Instrument Employed. 



Weston indicating volt- 
meter. 



General Electric record- 
ing ammeter. 

Weston milli-voltmeter 
with shunt. 

Weston milli-voltmeters 
with shunts. 



Weston voltmeters. 



Thomson watt-hour me- 
ter. 



Method of Making Mea- 
surements. 



Readings taken at one-sec- 
ond or two-second inter- 
vals. 

Continuous record. 



Read occasionally to check 
recording ammeter. 

Separate tests to determine 
the division of current be- 
tween the two motors. 
Readings at one-second or 
two-second intervals. 

Separate tests to determine 
the division of pressure 
between the two motors. 
Readings at one- second or 
two-second intervals. 

Readings at beginning and 
end of runs, number of 
revolutions of the disk be- 
ing noted for the interval. 
Readings were also taken 
at the beginning of the run 
and at the instant the con- 
troller was placed at the 
full parallel position. 



Time Measurements. 

In addition to the stop-watch readings mentioned above, the 
total time taken to reach the constant speed of 20 miles an hour 
was noted in each case. Besides these time measurements, the 
time-marking device and relay system employed in the service 
tests were used here, and upon the base lines of the current and 
speed records the five-second intervals were indicated. The 
star wheel on the controller was equipped with a circuit-break- 
ing device which was connected to the time-marking device of 
the recording ammeter. By means of a finger, which followed 
the indentations of the star wheel, the time-marker circuit was 



ACCELERATION TESTS OF A CITY CAR 205 

completed at the instant at which the controller cylinder passed 
from one position to another. By this means, the actual in- 
stant at which the controller was turning to a notch was accur- 
ately recorded with reference to the five-second marks on the 
recording ammeter record. 

Speed Measurements. 

The speed was measured by means of an "Apple" ignition 
generator, driven by the car axle in a manner similar to that 
described in the service tests of Chapter II, a chronograph being 
employed to give a graphical record of the armature pressure 
readings. The time and distance measurements were used as 
a check on the speed curve. 

Distance Measurements. 

The car was started from a given point in all tests. The dis- 
tance in which it was desired to turn on the controller to full 
parallel was carefully measured off in each case, and a stake was 
placed alongside the track at this point. In addition, the time 
of passing fixed points on the track was recorded on the base 
line of the speed record in a manner similar to that by which the 
controller notches were recorded on the current curve. These 
distance records were produced by means of a circuit-breaker 
carried on the bottom of the car body, and operated by wire 
trippers fastened to the track. The general arrangement of 
this apparatus is shown in Fig. 55. 

Contact Device. — The contact device. Fig. 55, was securely 
fastened to the running board of the car, and in such a position 
as to bring the contact breaker arm P just outside the rail, and 
its extremity about one-fourth inch below the head of the rail. 

The mechanism was moimted upon a block A made of one- 
inch white pine. It consisted essentially of a hickory arm P, 
pivoted at D, on a one-fourth inch bolt, and held in its normal 
position by the spiral springs S S, and the wooden guide G. 

The arm P was partially covered with sheet brass B, which 
served to conduct the current. This brass covering was con- 
nected to one side of the relay circuit through the bolt D, and 



206 



ELECTRIC RAILWAY TEST COMMISSION 



through a strip of brass fastened to the inner side of the guide 
G. The connection to the other side of the circuit was made by 
means of the contact C, which consisted of a sheet of brass 
sprung into grooves cut in the block A. 

The guide G was held in place by two bolts h h, provided with 
thick felt washers F F, and sheet brass washers d d. The felt 




Fig. 55. — Contact Device for Distance Measvfements. Acceleration Tests. 

washers served the double purpose of holding the guide at the 
proper distance from the block and of deadening the blow of the 
arm P. They also aided the springs S Sin restoring the arm to 
its normal position. The brass washers protected the v/ood and 
served as a fastening for the springs S S. 

The device was operated by wickets made of steel wire, and 
driven into the ties at certain intervals along the track. One of 
these wickets is shown at W. These wickets or "trippers" were 



ACCELERATION TESTS OF A CITY CAR 



207 



placed close together at the end of the track from which the 
starts were made, in order to give fairly uniform time intervals, 
thus insuring accuracy throughout the entire distance. 

Fig. 56 shows in detail the connections used with this appa- 
ratus, the circuit breaker being indicated at K. When the cir- 
cuit is opened by the operation of the switch arm, the armature 
of the relay r.^ is released, and a contact is made which completes 
the circuit through the battery B, and the electro-magnet r^, 




Fig. 56.— Relay Circuits for Time and Distance Measurements. Acceleration Tests. 



which latter, by means of the pen-point p, makes a record on the 
chronograph cylinder, C. 

This diagram also shows the circuit of the time-marking de- 
vice. Five-second impulses of current are produced in this cir- 
cuit by the periodical closing of the circuit by means of the 
rotating switch /b, which is a part of the chronometer. The cir- 
cuit is completed through the relay r^ and the dry cell battery 
h, so that, when the circuit is completed at each five-second in- 
terval, a record is produced as before upon the chronograph 
cylinder. A vibrating bell r^ is connected in parallel with the 
relay r^, and this gives the signal for all five-second readings, 
which are made on other instruments. 



208 ELECTRIC RAILWAY TEST COMMISSION 

WORKING UP THE RESULTS. 

It was not only important to take certain data simultane- 
ously, but it was also necessary that these data be taken at cer- 
tain time intervals, and that the time of start and stop of the car 
should be accurately known with respect to these time inter- 
vals. It was only by proceeding in this way that the exact rela- 
tion of all data could be fixed. With the stop watch, the total 
time of run from the instant the controller was turned to the 
first notch until the car attained a fixed speed of 20 miles an 
hour, was obtained. From the current record were obtained 
not only the actual value of the current at every instant at 
which current was being taken, but also the actual instant 
at which the current was applied and the instant at which it was 
cut off. Accurate records, with reference to the five-second 
readings of the indicating instruments, were made on the am- 
meter and speed records at five-second intervals. 

It is evident that all of these readings may be accurately 
correlated with the records of the current and speed. In addi- 
tion, the instant of passing each individual notch of the 
controller was indicated on the current record, and the time of 
passing given points on the track was shown on the speed 
record. 

In working up the final results, it was often necessary to go 
from one to another of the various sources of information in 
order to obtain a complete knowledge of the conditions exist- 
ing at any given instant. The records were all carefully worked 
over, and the various data were synchronized between the differ- 
ent sources of information. 

The Current Curves. 

The twenty current curves, for each of the five conditions of 
acceleration considered, were averaged by superimposing the 
various individual records one upon the other. Each indivi- 
dual record was also integrated, and the average curve was 
made to correspond in area as well as in shape to the average of 



ACCELERATION TESTS OF A CITY CAR 209 

the current curves. The exact elapsed time from the start to 
the passage of each of the controller notches was next obtained 
for each of the individual twenty curves, and the average time 
for each notch was found. In a similar manner the maxi- 
mum current at each of the controller notches for each of the 
twenty individual curves of a run was found, and the average 
maximum value at each notch was obtained for each of the 
tests. 

The average current curve was checked by means of these data, 
and it was also made to conform in its characteristic features 
to the general shape of the individual curves for the given test. 

The Pressure Curves. 

The pressure readings were taken at either one-second or at 
two-second intervals in each test. The readings at correspond- 
ing time intervals were averaged for the twenty runs in a given 
test. The average pressure curve was then drawn from the 
data thus obtained. 

The Power Curves. 

The power data were obtained directly from the current and 
pressure data, values being found for each second interval. The 
power curves were then plotted, due consideration being given 
to variations in current and pressures between the points ob- 
tained. The average power over a given interval of time was 
obtained by dividing the total energy for the interval by the 
elapsed time. 

The Energy Curves. 

The energy curves were obtained by integrating the power 
curves over one-second intervals, the energy at each second 
point being thus obtained. A straight line has been drawn 
from point to point, no attempt being made to show the varia- 
tions in energy consumption between these points. These total 
energy readings were checked up with the data, as shown by 
the watt-hour meter. 



210 ELECTRIC RAILWAY TEST COMMISSION 

The Speed Curves. 
As in previous tests, the data for the speed curves were ob- 
tained directly from the speed record made by means of the 
"Apple" ignition generator, driven by the car axle, the pressure 
of which was recorded by means of a Weston voltmeter and the 
chronograph record. In working up the speed curve it was 
necessary to first obtain the actual time of start of each run. 
This was done by finding the exact instant of start with refer- 
ence to the five-second scores on the recording ammeter record 
for the particular run, and transferring these data to the speed 
curve by means of the five-second scores on the latter curve. 
The "second" intervals from the start were then carefully 
measured and ordinates erected. The various speed curves for 
each condition of acceleration were worked up in this manner, 
and a table was compiled showing the speed for each of these 
runs at the "second" intervals. From these data the average 
speed of all runs for a given condition of acceleration was ob- 
tained for each "second" interval from the start. From these 
data the speed curves were plotted. Since all runs for a given 
condition of acceleration did not have the same total time inter- 
val, it was necessary to obtain the average time of running, in 
each case, from the start to the point at which the fixed speed 
of 20 miles an hour was reached. This was done by taking 
the average time of each run, as shown by the stop watch. 

The Distance Curves. 
As previously stated, the times of passing certain fixed points 
on the track were indicated on the speed record by means of 
an electro-magnet, which was operated by the circuit-breaking 
device on the car coming in contact with the wire trippers on 
the track. These data were used in obtaining the distance 
curve. The wire trippers were set close together at the begin- 
ning, and the distance between trippers became greater and 
greater toward the end of the test-track limits. This arrange- 
ment of trippers was necessary because of the slow speed at the 
start, and the gradual increase of the speed to a maximum value 



ACCELERATION TESTS OF A CITY CAR 211 

at the end of a test. Nineteen trippers in all were used and the 
distances in feet, at which these trippers were placed from the 
starting points were as follows : 0, 5, 10, 15, 20, 25, 35, 50, 65, 
80, 100, 120, 140, 165, 190, 240, 290, 340, and 390. 

A number of runs were selected for each condition of accelera- 
tion, and the exact instant of passing each tripper was ascertained 
and recorded for each of these nms. The average time of pass- 
ing each tripper was then found for each condition of accelera- 
tion, and the distance curve was plotted from these values. 

Since the distance traveled is the summation of the speed 
and time from the start to the point considered, it is evident 
that the distance curve may be obtained by summing up or in- 
tegrating the area under the speed curve for any interval from 
the start. Such integrations were made for each of the curves, 
and the distances thus determined were then checked against 
the actual distances traversed, as shown b}^ the distance mea- 
surements. 

Division of Current and Pressure. 

Readings were taken of the individual currents and pressures 
of the motors at various instants throughout each run. These 
data show that the motors were very evenly matched, the pres- 
sure being practically the same on each motor for the series posi- 
tion of the controller, and the current dividing practically 
equally between the motors for the parallel position of the con- 
troller. As the division of current and pressure between the 
motors have been shown in the Service Tests in Chapter II, they 
will not be discussed here. 

Results of the Tests. 

Some of the more important numerical results of the various 
acceleration tests made upon the single-truck city car are shown 
in tabular form in the synopsis at the beginning of the chapter. 
The results are shown more completely in graphical form in 
Figs. 57 to 66, inclusive. These graphical representations have 
been divided into two sets of curves for each test. One set 



111. 



212 ELECTRIC RAILWAY TEST COMMISSION 

shows the electrical data, while the other shows the speed and 
distance data. The graphical results for each condition of accel- 
eration are accompanied by a general log sheet. 

The plates showing the electrical data are plotted on a time 
base, and the curves show the variations in the pressure, current, 
power, and energy in each case. The acceleration curve is also 
placed on this sheet. The plates showing the speed and dis- 
tance data are also plotted on a time base, and give the speed, in 
miles per hour, and the distance traveled in feet. Figs. 57, 59, 
61, 63, and 65 are plotted from the electrical data, while Figs. 
58, 60, 62,. 64, and 66 are plotted from the speed and distance 
data. 

GENERAL LOG SHEET OF TEST NO. 13. 

Pressure. — Average line pressure, 521.0 volts. 

Distance. — Distance traversed from the start to the point 
at which the controller was at the full parallel position, 40 ft.; 
distance traversed from the start to the point at which the speed 
reached 20 miles an hour, 286.6 ft. 

Time. — Interval from the start to the point at which the 
controller was at the full parallel position, 4.52 seconds; inter- 
val from the start to the point at which the speed became 20 
miles an hour, 14.51 seconds. 

Acceleroiion. — Average acceleration for the test run, 1.33 
miles per hour per second; maximum acceleration, 2.50 miles 
per hour per second. 

Current. — Average current for the test, 146.7 amperes; maxi- 
mum current for the series position of controller, 172.0 am- 
peres; maximum current for the parallel position of controller, 
298.5 amperes; the square root of the mean square value of 
the current for the run, 160.9 amperes; the form factor (square 
root of the mean square of the current divided by the average 
current), 1.097. 

Power. — Average power for the test, 74.6 kilowatts; maxi- 
mum power at the series position of the controller, 89.4 kilo- 
watts ; maximum power at the parallel position of the controller, 
149.7 kilowatts. 



ACCELERATION TESTS OF A CITY CAR 



213 



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110 ^ 

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60 300 



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80 100 




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Fig. 57. — Electrical Data of Test No. 13. 



214 



ELECTRIC RAILWAY TEST COMMISSION 



Energy. — Energy required for the test, 301.0 watt-hours; 
energy used from the start to the point at which the controller 
was at the full parallel position, 108.1 watt-hours. 



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Seconds 2 4 6 8 lU la 14 

Fig. 58. — Speed and Distance Data, Test No. 13. 
GENERAL LOG SHEET OF TEST NO. 14. 

Pressure. — Average line pressure, 516 volts. 

Distance. — Distance traversed from the start to the point at 
which the controller was at the full parallel position, 70 ft. ; dis- 
tance traversed from the start to the point at which the speed 
reached 20 miles an hour, 305.5 ft. 

Time. — Interval of run from the start to the point at which 
the controller was at the full parallel position, 6.63 seconds; in- 






ACCELERATION TESTS OF A CITY CAR 



215 



terval of nin from the start to the point at which the speed be- 
came 20 miles an hour, 16.10 seconds. 

Acceleration. — Average acceleration for the test, 1.25 miles 
per hour per second; maximum acceleration, 2.32 miles per hour 
per second. 





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4 6 8 10 .12 14 

fig. 59. —Electrical Data of Test No. 14. 






Current. — Average current for the test, 132.2 amperes; 
maximum current for the series position of controller, 139.6 
amperes; maximum current for the parallel position of con- 
troller, 220.4 amperes; the square root of the mean square 
value of the current for the run, 142.8 amperes; the form factor 



216 



ELECTRIC RAILWAY TEST COMMISSION 



(square root of the mean square of the current divided by the 
average current), 1.08. 

Power. — Average power for the test, 64.6 kilowatts; maxi- 
mum power at the series position of the controller, 71.6 kilo- 
watts ; maximum power at the parallel position of the controller, 
111.0 kilow^atts. 

Energy. — Energy required for the test, 289.2 watt-hours; 



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Fig. 60. — Speed and Distance Data, Test No. 14. 

energy used from the start to the point at which the controller 
was at the full parallel position, 122.7 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 15. 

Pressure. — Average line pressure, 513 volts. 

Distance. — Distance traversed from the start to the point 



ACCELERATION TESTS OF A CITY CAR 



217 



at which the controller was at the full parallel position, 100 ft. ; 
distance traversed from the start to the point at which the speed 
reached 20 miles an hour, 322.5 ft. 

Time. — Interval of run from the start to the point at which 
the controller was at the full parallel position, 8.88 seconds; 
interval of run from the start to the point at which the speed 
became 20 miles an hour, 17.90 seconds. 






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Fig. 61. — Electrical Data of Test No. 15. 



Acceleration. — Average acceleration for the test, 1.12 miles 
per hour per second; maximum acceleration, 2.32 miles per 
hour per second. 

Current. — Average current for tne test, 122.1 amperes; 
maximum current for the series position of controller, 139.3 am- 
peres ; maximum current for the parallel position of controller, 
191.2 amperes; the square root of the mean square value of 
the current for the run, 127.1 amperes; form factor (square 



218 



ELECTRIC RAILWAY TEST COMMISSION 



root of the mean square of the current divided by the average 
current), 1.041. 

Power. — Average power for the test, 62.1 kilowatts; maxi- 
mum power at the series position of the controller, 71.2 kilo- 




2 4 G 8 10 12 14 16 

Fig. 62. — Speed and Distance Data, Test No. 15. 

watts; maximum power at the parallel position of the controller, 
94.2 kilowatts. 

Energy. — Energy required for the test, 308.3 watts-hours; 
energy used from the start to the point at which the controller 
was at the full parallel position, 158.6 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 16. 

Pressure. — Average line pressure, 517 volts. 
Distance. — Distance traversed from the start to the point 
at which the controller was at the full parallel position, 150 ft. ; 



ACCELERATION TESTS OF A CITY CAR 



219 



distance traversed from the start to the point at which the speed 
reached 20 miles an hour, 339.1 ft. 

Time. — Interval of run from the start to the point at which 
the controller was at the full parallel position, 11.33 seconds; 
interval of run from the start to the point at which the speed 
became 20 miles an hour, 19.09 seconds. 

Acceleration. — Average acceleration for the test, 1.05 miles 



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per hour per second; maximum acceleration, 2.32 miles per 
hour per second. 

Current. — Average current for the test, 115.0 amperes; 
maximum current for the series position of controller, 135.3 
amperes; maximum current for the parallel position of con- 
troller, 158.2 amperes; the square root of the mean square 
value of the current for the inm, 119.4 amperes; form factor 
(square root of the mean square value of the current divided by 
the average current), 1.038 amperes. 



220 



ELECTRIC RAILWAY TEST COMMISSION 



Power. — Average power for the test, 59.8 kilowatts; maxi- 
mum power at the series position of the controller, 70.0 kilo- 
watts ; maximum power at the parallel position of the controller, 
80.0 kilowatts. 

Energy. — Energy required for the test, 317.1 watt-hours*, 



600 20 



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Seconds 2 4 6 8 10 12 14 16 18 20 

Fig. 64. — Speed and Distance Data, Test No. 16. 

energy used from the start to the point at which the controller 
was at the full parallel position, 182.9 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 17. 

Pressure. — Average line pressure, 517 volts. 

Distance. — Distance traversed from the start to the point at 
which the controller was at the full parallel position, 200 ft.; 
distance traversed from the start to the point at which the 
speed reached 20 miles an hour, 377.2 ft. 



1 



ACCELERATION TESTS OF A CITY CAR 



221 



Time. — Interval of run from the start to the point at which 
the controller was at the full parallel position, 13.90 seconds ; 
interval of run from the start to the point at which the speed 
became 20 miles an hour, 21.09 seconds. 

Acceleration. — Average acceleration for the test, 0.95 miles 
per hour per second; maximum acceleration, 2.32 miles per 
hour per second. 

Current, — Average current for the test, 99.7 amperes; maxi- 



51 

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Fig. 65. — Electrical Data of Test No. 17. 



22 



mum current for the series position of controller, 115.2 amperes ; 
maximum current for the parallel position of controller, 127.2 
amperes; the square root of the mean square value of the cur- 
rent for the run, 101.7 amperes; the form factor (square root 
of the mean square value of the current divided by the average 
current), 1.01. 

Power. — Average power for the test, 50.6 kilowatts; maxi- 
mum power at the series position of the controller, 59.8 kilo- 



222 



ELECTRIC RAILWAY TEST COMMISSION 



watts; maximum power at the parallel position of the con- 
troller, 65.1 kilowatts. 

Energy. — Energy required for the test, 297.0 watt-hours; 
energy used from the start to the point at which the controller 
was at the full parallel position, 189.4 watt-hours. 

Discussion of Results. 
A study of the curves given in Figs. 57 to 66, inclusive, brings 
out some very interesting results. 

















































§ 2 
600 20 




















































































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Fig. 66. —Speed and Distance Data, Test No. 17. 



I 

M 
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2.5 



2.0 



22 



The Pressure Curves. — The pressure curves all show more 
or less fluctuation. This is due to the variations in the current 
taken by the car. However, these variations are negligible, in 
so far as their bearing on the acceleration tests is concerned. 
The reasons for this are : first, that the acceleration tests were 
started between the times of passing of the Intramural cars, 
which were supplied with power from the same source; second, 
the maximimi duration of any one run was not greater than 21 



ACCELERATION TESTS OF A CITY CAR 



223 



seconds; and, third, twenty runs were taken for each test, and 
the results averaged. An inspection of the pressure curves 
shows a general tendency for a fall in pressure as soon as the 
controller is turned on, and a rise in pressure as the current 
decreases toward the end of test. A depression is found at the 
point where the maximum current is taken for the series posi- 
tion, and again at the corresponding point for the parallel posi- 



125 



100 



76 300 



50 2U0 



26 100 



Peet to Turn Controller o 
to Full Parallel 











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20 40 60 80 100 120 1«) 160 180 200 

Fig. 67. — Summary of Electrical Data, Acceleration Tests of Single-Truck Car. 



tion. It will also be noticed that the pressure remains more 
nearly uniform with the slower accelerations, there being very 
little change in the pressure with the slowest acceleration, be- 
yond the characteristic drop at the points of maximum accel- 
eration for the series and parallel positions of the controller. 

The Current Curves. — While the current curves all have 
the same characteristic shape, it is seen that the maximum cur- 



224 ELECTRIC RAILWAY TEST COMMISSION 

rent both for the series and parallel positions of the controller, 
is very much greater for the rapid acceleration than for the 
slower ones. It will also be noted that while the maximum 
current at both the series and parallel positions decreased as 
the acceleration became slower, the maximum current at the 
parallel position decreased much faster than did the maximum 
current at the series position. This is very clearly brought 
out in the curves shown in Fig. 67. The average current for 
the test is somewhat lower than the maximum current for the 
series position of the controller. 

The Power Curves. — The power curves necessarily have 
the general characteristic shape of the current curves, since the 
variations in pressure are not marked. The same general 
results that occur in the case of the current curves are noted 
here. While the maximum power in both the series and par- 
allel positions of the controller decreased very materially with 
the slower accelerations, it is seen by an inspection of Fig. 67 
that the decrease in the maximum power at full parallel is very 
much greater than that for full series. The average power for 
the test is less than the maximum power for the series position 
of the controller. 

The Energy Curves. — While the energy curves have the 
same characteristic form for each of the five conditions of accel- 
eration, they vary somewhat because of the fact that the power 
curves are considerably different in form in the various tests. 
While the time required to reach a speed of 20 miles an 
hour was considerably shorter for the more rapid accelerations, 
the average power for the test was much greater. The conse- 
quence is that, in the tests under consideration, the total energy 
taken by the car in reaching this speed was very nearly the 
same for all tests made. An inspection of the total energy 
curve in Fig. 67, shows a tendency for the total energy to be- 
come a maximum at the more rapid accelerations, and again 
at the intermediate accelerations. The data at hand, how- 
ever, hardly warrants the drawing of conclusive deductions. 

The Speed Curves. — The speed curves show a general 



ACCELERATION TESTS OF A CITY CAR 



^^5 



tendency for a rapid increase in the speed at the start, and a 
gradual falling off in this increase as the maximum speed is 
reached. The speed curves are smoother and more uniform 
with the higher accelerations, and have quite a characteristic 
bend in them for the slower accelerations. The bend is due to 
the fact that in the tests with the slower accelerations, the motors 



20 



8.0 12 



2.6 10 



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100 



Feet to Turn Controller 
to FoU Parallel 



100 120 140 160 180 200 



Pig. 68. —Summary of General Data, Acceleration Tests of Single-Truck Car. 

were run for a considerable time on the sixth notch of the con- 
troller, with the consequent tendency of a decrease in accel- 
eration. 

The Acceleration Curves. — The acceleration curves show 
a maximum acceleration at the start, this maximum being ap- 
proximately two and one-third miles per hour per second for 
all tests. The results show a slightly higher acceleration than 
this in the test with the most rapid acceleration, but there 




226 ELECTRIC RAILWAY TEST COMMISSION 

appears to be no particular reason for this. The controller was 
turned to the first notch under practically the same conditions 
in all tests, and in each case the acceleration was a maximum at 
the start. It will be noted, however, that this maximum accel- 
eration continues throughout a greater portion of the run with 
the more rapid accelerations. The acceleration curves have 
the same general shape in all tests, starting with a maximum 
and gradually falling off to a minimum value at the end of 
the test. In the curves for the slower accelerations a rise 
will be noted toward the middle of the run. This is due to the 
falling off in speed during this portion of the run, as above men- 
tioned. 

The variations in maximum acceleration, and also in aver- 
age acceleration for the various tests, are shown in Fig. 68. 
AVhile the maximum acceleration remained practically constant 
for all tests, the average acceleration decreased with the slower 
accelerations. 

The Distance Curves. — The distance curves all have the 
same characteristic shape, as slight variations in speed have but 
little effect upon their general form. The total distance trav- 
ersed, however, is quite different for the various tests. The 
distance curve in Fig. 68 shows the variation in distance trav- 
eled, as the acceleration is changed. 



CHAPTER VI. 
ACCELERATION TESTS OF AN INTERURBAN CAR. 



Object of the Tests. 

The principal object of these tests was to study the various 
factors entering into the acceleration of an interurban car when 
this acceleration is accomplished by means of the automatic 
action of a pneimiatic system of control. While it was intended 
to consider primarily the energy consumption, maximum cur- 
rent and maximum power, the tests also included the measure- 
ment of such variables as time, current, pressure, speed, accel- 
eration, and distance traversed. Tests were made for the series 
a3 well as for the parallel positions of the master controller. In 
addition, some attempts were made to ascertain the effect of 
varying the operation of the limit switch, which controlled the 
closing of the contacts for the various connections of the turret 

controller. 

Synopsis of Results. 

The table on the following page shows some of the principal 
results of the acceleration tests on this car. The data of test 
No. 18 was obtained when the car was accelerated with the 
master controller in the series position. The data of test No. 
19 was obtained, correspondingly, when the master controller 
was turned immediately to the parallel position, and the car 
accelerated with the controller in this position. 

General Conditions of the Tests. 

All of the acceleration tests upon the interurban car were 
carried out on a stretch of track between Noblesville and Carmel, 
on the Northern Division of the Indiana Union Traction Com- 

227 



228 



ELECTRIC RAILWAY TEST COMMISSION 



Table No. XXXI. — Synopsis of Results. Acceleration Tests of an Inter- 
urban Car. 



Running Position of Controller 

Maximum Speed (M.P.H.) 

Speed at Full Series (M.P.H.) 

Speed at Full Parallel (M.P.H.) 

Elapsed Time for the Test (Seconds) . . . 

Elapsed Time to Full Series (Seconds) . . 

Elapsed Time to Full Parallel (Seconds) 

Distance for the Test (feet) 

Distance to Full Series (Feet) 

Distance to Full Parallel (Feet) 

Average Current (Amperes) 

Maximum Current (Amperes) 

Average Pressure (Volts) 

Average Power (Kilowatts) 

Maximum Power (Kilowatts) 

Total Energy (Watt-hours) 

. A 1 X- (Miles per hour) 

Average Acceleration ^^ — ^ . . 

Seconds 

(Miles per hour) 



Maximutn Acceleration 



Seconds 



Test 

No. 18. 



Series 
25.0 
11.6 



55.5 
9.10 



1,510 
83.0 



204.0 
490.0 
519.1 
106.9 
240.1 
1,648 

0.45 
1.52 



Test 
No. 19. 



Parallel 

38.0 

12.4 

22.3 

65.5 

9.35 

20.26 

2,540 

87.0 

345.0 

414.5 

623.0 

440.3 

178.7 

236.8 

3,252 

0.58 
1.55 



pany's system. Its exact location was between poles Nos. 
10,909 and 10,883. The spacing of the poles was 100 ft. and the 
stretch of track used, therefore, was 2600 ft. in length. It 
was tangent and level throughout the entire distance. 

The car used for the acceleration tests was the one also used 
for the service tests considered in Chapter IV. This inter- 
urban car is fully described and illustrated in Chapter I. The 
car equipped and ready for service weighed 74,530 lbs., and 
the total weight under the conditions of test was 79,320 lbs., 
or approximately 39.66 tons. The load was the same as in the 
service tests described in Chapter IV. As previously stated, 
the motive power equipment consisted of four Westinghouse 
No. 85 motors, which have a rating capacity of 75 horse power 
each. 

THE CONTROL SYSTEM. 

The car was equipped with the latest type of the electro- 
pneumatic, multiple-unit control system of the Westinghouse 



ACCELERATION TESTS OF AN INTERURBAN CAR 229 

Electric and Manufacturing Company. The essential features of 
this system are: 

(1) The Switch Group or turret controller for each car in the 
train consists of a number of switches suitably arranged for 
making the necessary connections of the motor circuits. The 
switches are operated by air-driven pistons, working in small 
cylinders, the supply of air to which is controlled by valves 
operated by electro-magnets. 

(2) A Train Line, connecting all of the cars in the train, and 
containing a suitable number of circuits for operating the electro- 
pneumatic valves in the switch groups. The train line is sup- 
plied with current from storage batteries placed in each car. 

(3) A Master Controller in each car arranged to make con- 
nections through the train line to all of the switch group operat- 
ing magnets. 

(4) A Reverse Switch, electro-pneumatically operated, for 
reversing the relative connection of motor armatures and fields, 
and hence the direction of motion of the car. 

(5) A Limit Switch, for controlling the rate at which current 
can be drawn by the motors, and which thus limits the accel- 
eration of the train to a pre-determined value. 

The Switch Group. — Fig. 69 shows in cross-section the 
switch group, consisting of thirteen radially arranged switches 
or contactors, surroimding a powerful coil which magnetically 
blows out the arcs. Each switch unit consists of three essen- 
tial parts: a contactor, an air cylinder for operating the same, 
and an electro-pneumatic valve which controls the admission 
of air to the cylinder. Air is drawn from an auxiliary reser- 
voir, which in turn receives it from the main air brake reser- 
voir. The air is received at the switch group in the chamber 
C, Fig. 69. The pressure in this chamber is 70 lbs. per square 
inch. From this chamber the air passes to the electro-pneu- 
matic valve, M. As previously stated, the electro-magnet 
operating the valve receives its current from the train line, and 
when energized the core of the solenoid is lowered, and air is 
admitted to the upper end of the cylinder A. The air presses 



s- 



230 



ELECTRIC RAILWAY TEST COMMISSION 



the piston downward against the resistance of a strong spiral 
spring, thereby forcing together the copper-faced jaws of the 
contactor K, and closing the motor circuit. When the current 
is cut off from the electro-pneumatic valve M, the core rises, 
closing the inlet valve and opening the exhaust to the atmos- 
phere. The piston is then forced upward by the spiral spring, 
and the contactor circuit is opened. The unit switches, com- 
prising the switch group, are covered with a sheet-iron case to 
protect the mechanism from dirt and moisture. 




Fig, 69. — Switch group of the Westinghouse Electro-Pneumatic System of Control. 



The plan for connecting the motors is known as the bridging 
system. The arrangement of the motor circuits is shown in Fig. 
70. The contactors or unit switches are numbered from one 
to thirteen, and these are closed in succession in such a way as 
to produce the several connections of the series-parallel arrange- 
ment. The starting resistances are short circuited by switches 
1, 2, 3, 9, 10, and 11. 

The Train Line. — The train line consists of seven small 
wires, which run from end to end of each car, terminating in 



ACCELERATION TESTS OF AN INTERURBAN CAR 231 

couplers into which plug jumpers are inserted for the purpose 
of connecting the several cars of the train. These wires 
are connected to the master controller, and they are also led 
to the switch group located near the center of the car. They 
are supplied with storage battery current at about fourteen 
volts. 

The Master Controller. — The master controller consists 
of a small rotating cylinder, upon which are mounted copper 
segments which make connection between contact fingers in 
which branch leads from the train line terminate, there being 
one contact finger for each train line wire. As this cylinder is 



Unit Switch 
^6^ 



'I 
1 



Motor rte.1 



Unit 



I 



5 I e Switch 
"Mir 



Unit Switches 



^ 



;^A/VW<>m-^A/\/\AAA/\AA/VWV^% 



Unit Switch 



Unit Swit&hes 



^ Unit 
Switch 



] 



Motor No. 2 



cUnit 
p Switeh 



-• •- 
10 3 I 

Unit Switches 

Fig. 70. — Diagram of Connections, Westinghouse Electro-Pneumatic System of Control. 



rotated by means of a handle, the various contactors of the 
train line are supplied with current, and the corresponding 
electro-pneumatic valves in the switch groups are energized. 
The master controller is arranged for three running conditions. 
The first running notch is known as the switching notch, at 
which the motors are in series-parallel with all of the resis- 
tances in circuit. The series running notch is the same, but with 
the resistances cut out. On the parallel running notch the 
motors are connected in parallel with the resistances cut out. 
The intermediate positions are as usual in the series-parallel 



232 ELECTRIC RAILWAY TEST COMMISSION 

control system. The master controller handle is automatically 
brought to the "off" position if released. 

The Reverse Switch. — The reverse switch consists of a 
rotating cylinder placed under the car, and operated by an air 
cylinder mechanism. The cylinder carries copper segments, 
which connect the armatures and fields of the various motors 
in one relative direction or another, depending upon the posi- 
tion of the cylinder. The position of the reverse switch is 
controlled by the master controller by means of an electro- 
pneumatic valve. 

The Limit Switch. — The function of the limit switch is to 
prevent excessive draft of motor current by limiting the rate 
at which the electro-pneumatic valves in the switch groups can 
be operated. It consists of a solenoid and plunger, the former 
being connected in one of the motor circuits. To the plunger is 
attached a copper disc, which normally bridges across two con- 
tacts in the control circuit. When the motor current is exces- 
sive the core of the solenoid is raised, breaking the control cir- 
cuit. All of the pneumatic valves, which have been previously 
energized will remain so, but no new valves can be operated 
until the solenoid core falls again. The operation of the limit 
switch is susceptible of adjustment, but it is generally set for 
a given maximum current, according to the equipment used 
and the acceleration desired. 

In addition to the essential devices described above, the 
system includes a number of auxiliary features which tend to 
increase the reliability of operation. Complete descriptions of 
the entire equipment may be found in the Street Railway Jour- 
nal, Volume XXII, 1903, page 617, and Volume XXV, 1905, 
page 809. A description is also given in the Electric Club 
Journal, Volume II, 1905, page 207. 

General Description of the Tests. 

The tests consisted primarily in starting the car from rest 
at a given point, by turning the master controller immediately 
to a pre-determined position, and taking continuous measure- 



ACCELERATION TESTS OF AN INTERURBAN CAR 233 

ments of all of the quantities involved until a certain speed was 
reached. This speed was taken at 25 miles an hour for the 
series position of the controller, and at 38 miles an hour for the 
parallel position. 

The maximum speeds attained do not represent the highest 
values of speed which would be reached by the car if it were per- 
mitted to continue running under the conditions of the tests 
on a tangent level track. In the case of the test with the master 
controller in the parallel position, the speed of 38 miles an hour 
was recorded practically the limit of speed to be obtained in 
the 2600 ft. of level tangent track available. A one per cent 
grade was encountered immediately after the 2600 ft. had been 
traversed, and it was not considered advisable to continue the 
acceleration tests beyond the distance indicated. In the case 
of the acceleration tests with the master controller in the series 
position, a limiting speed of 25 miles an hour was taken in order 
to insure a distinct point at which to consider the test ended. 
Beyond this point the speed variations are small and not very 
clearly defined, although the speed continues to increase slowly. 

Because of the fact that it was necessary for the company to 
make use of the car on a certain day, it was impossible to make 
the acceleration tests as comprehensive as had been planned, 
as but one-half day was available for actually conducting this 
series of tests. 

Two runs only were made with the master controller in the 
series position at the start. These two runs were made under 
exactly the same conditions, except for the variations in line 
pressure, and the data obtained in them has been averaged in 
working up the results designated as Test No. 18. 

Eight runs were made with the master controller in the par- 
allel position at the start. All of these runs were under the 
same conditions, excepting that it was attempted to vary the 
conditions by changing the adjustment of the limit switch of 
the control apparatus by means of small weights. The eight 
runs were made in pairs, four different adjustments of the limit 
switch being considered. These four conditions were with the 



^j 



234 ELECTRIC RAILWAY TEST COMMISSION 

limit switch weighted as follows: (a) zero ounces, (h) 0.286 
ounces, (c) 0.859 ounces, (d) 1.430 ounces. 

It was found that the weights employed were not sufficient 
to cause any very considerable difference in the operation of 
the controller as the car was accelerated. Lack of time pre- 
vented further investigation with heavier weights. In work- 
ing up the results these eight runs have been averaged together, 
and the average values used in plotting curves. This practi- 
cally amounts to the same thing as the average of a series of 
eight runs, with the limit switch adjusted for a current slightly 
heavier than allowed by the normal adjustment of the apparatus. 
As the data for the four conditions of adjustment of the limit 
switch show some variations which appear to follow certain 
laws, these data are considered in more detail in the discussion 
of results. As the controller was entirely automatic in its 
action, there was no practicing of starts necessary in order to 
obtain uniform acceleration. At the time the tests were made 
the car appeared to start smoothly, and no objectionable jerks 
were experienced, as succeeding contacts were made on the 
group switch. 

The arrangements for the acceleration tests on this car may 
be briefly set forth as follows: 

Test No. 18. — In this test the master controller was turned 
at once to the series position, the car being at rest at the instant 
of start. The final contact for the series position of the motors 
was made in 9.1 seconds from the start, when the car had trav- 
ersed 83 ft. The fixed speed of 25 miles an hour was reached 
in 55.5 seconds, when the car had traversed 1510 ft. 

Test No. 19. — In this test the master controller was turned 
at once to the parallel position, the car being at rest. The final 
contact for the series position of the motors was made in 9.35 
seconds, when the car had traversed 87 ft. The final contact 
for the parallel position of the motors was made in 20.26 sec- 
onds, when the car had traversed 345 ft. The fixed speed of 
38 miles per hour was reached in 65.5 seconds, when the car had 
traversed 2540 ft. 



ACCELERATION TESTS OF AN INTERURBAN CAR 235 
ORIGINAL MEASUREMENTS. 

In taking the original data for the acceleration tests on the 
interurban car, the recording devices were used which were em- 
ployed in the service tests on this car. They have been de- 
scribed and illustrated in Chapter IV. 

The original data obtained for the acceleration tests, may be 
divided into four general classes as follows: (a) those relating 
to electrical input, (b) those relating to time, (c) those relat- 
ing to speed, and (d) those relating to distance traversed. 

Electrical Measurements. 

The general method of taking the electrical measure- 
ments was the same as that employed in conducting the ser- 
vice tests on the interurban car, a record being made of the 
total current, line pressure, speed, and control current. The 
General Electric recording ammeter gave an additional graph- 
ical record of the current taken by the car. The method of 
procedure was for one person to give the signal for the turn- 
ing on of the controller, which was the starting signal for all 
the readings. 

In working up the results, the actual instant at which the 
current was turned on, as shown by the General Electric record- 
ing ammeter record, was taken as the starting point. The con- 
nections of the instruments were the same as in the service tests 
on this car, and are shown in Fig. 50. As seen from this dia- 
gram, the main current passed through the General Electric 
recording ammeter and the watt-hour meter, the latter instru- 
ment recording the total energy. Other electrical data ob- 
tained was the total car current as measured on the general 
recording apparatus, the line pressure, and the control current, 
all of which were recorded by means of the general apparatus. 
The shunt for the Weston milli- voltmeter giving the total cur- 
rent, was connected in the main circuit. The energy taken by 
the motor compressor was also obtained by means of a Duncan 
watt-hour meter. 



236 



ELECTRIC RAILWAY TEST COMMISSION 



The various electrical measurements which were made are 
shown in the following table: 



Quantity 
Measured. 



Line Pressure . . . 
Total Current . . 
Total Current . . 
Control Current, 
Total Energy . , 

Control Energy , 



Instrument Employed. 



Weston indicating volt- 
meter. 

General Electric recording 
ammeter. 

Weston milli - voltmeter 
with shunt. 

Weston ammeter. 



Thomson watt-hour meter. 



Duncan watt-hour meter. 



Method of Making Mea- 
surements. 



Continuous record by general 
recording apparatus. 

Continuous record by general 
recording apparatus. 

Continuous record by general 
recording apparatus. 

Continuous record by general 
recording apparatus. 

Readings at beginning and 
end of runs, number of 
revolutions of the disk be- 
ing noted for the interval. 

Readings at beginning and 
end of runs, number of 
revolutions of the disk be- 
ing noted for the interval. 



Time Measurements. 

The time of the beginning and end of each run was noted 
with a stop-watch. Besides these time measurements, the 
time-marking device and relay system employed in the service 
tests on the car were used. The five-second intervals were 
indicated upon the base lines of the records of the General Elec- 
tric recording ammeter, and upon the general recording appa- 
ratus. 

Speed Measurements. 

The speed was measured by means of an "Apple" ignition 
generator, driven by the car axle in a manner similar to that 
described in the service tests of Chapter IV; the armature pres- 
sure of this generator being recorded graphically by means of 
the general record apparatus. The time and distance data 
were used as a check on the speed curve. 



ACCELERATION TESTS OF AN INTERURBAN CAR 237 

Distance Measurements. 
The car was started from a given point in all tests, pole 10,909 
being directly opposite the center of the window in the front 
vestibule. At the instant of starting a record of this pole was 
made on the general recording apparatus, in a manner already 
described. In a similar way the observer made correspond- 
ing records, showing the instant at which each successive pole 
passed the center of the vestibule. As these poles were spaced 
exactly 100 ft. apart, the record gives an accurate determina- 
tion of the time-distance curve. 

The Control Measurements. 
In addition to the control current data as shown on the gen- 
eral record, and the control energy data as measured by the 
watt-hour meter, measurements were made after the comple- 
tion of the tests to determine the amount of energy taken by 
the motor compressor in compressing air between the limits 
used in the test. Data were also obtained showing the leakage 
of air from the piping system. In addition, a number of tests 
were made to determine the amount of air used in making appli- 
cations of the controller to the series position, and also to the 
parallel position. 

WORKING UP THE RESULTS. 

As in previous tests, instrimient readings were synchron- 
ized at certain intervals, and the time of the "start" and the 
"stop" of a test were accurately registered with respect to these 
time intervals. The exact instant at which the current was 
applied and the instant at which it was cut off, as well as the 
exact value of the current throughout a test were obtained 
from the current record. The data showing the line pressure, 
speed, and the instant of passing each pole were obtained from 
the general record. 

The records were carefully worked over, and the various 
data correlated among the different sources of information. 
By proceeding in this manner, it was possible to obtain a com- 
plete knowledge of the conditions existing at any instant. 



238 ELECTRIC RAILWAY TEST COMMISSION 

The Current Curve. 

The exact time of "start" in each case was obtained from 
the current curves, as shown by the General Electric recording 
ammeter, the start of a rim being assumed at the instant when 
the current was turned on. The current curves of the record- 
ing ammeter were worked up in the following manner. Ordi- 
nates were erected at the starting point, and at each five-sec- 
ond point thereafter, up to the end of the test. The exact 
ordinate corresponding to each of these points was obtained 
by correcting for the curvature inherent in the record, as ex- 
plained in Chapter I of the Report. The average of the cur- 
rent records, for the two runs made with the master controller 
at the series position, was taken for each similarly situated 
five-second point, and a current curve adjudged to be typical 
of the "series" position was plotted from these averages. In 
a similar manner, the average current, for the eight runs made 
with the master controller at the parallel position, was taken 
for each of the five-second points from the "start." The typi- 
cal current curve for the "parallel position" in acceleration was 
plotted from these results. 

The exact elapsed time from the start to the passage of each 
of the controller notches was obtained for each individual 
curve, and the average time for each notch was found. In a 
similar manner the maximum current at each of the controller 
notches for each individual curve was obtained, and the aver- 
age maximum current at each of the notches foimd. This was 
done both for the condition of "series" acceleration, and for 
that of "parallel" acceleration. 

The average current curve for each of the two conditions was 
checked by means of these data, and it was also made to con- 
form in its characteristic features to the general shape of the 
individual curves for the given condition of acceleration. 

The Pressure Curves. 

The exact instant of start was found for each pressure curve 
by ascertaining the relation between the five-second score 



ACCELERATION TESTS OF AN INTERURBAN CAR 239 

marks and the instant of start on the current curve as shown 
by the General Electric recording ammeter, and transferring 
these data to the pressure curve on the general record. The 
"typical" pressure curves were then worked up in a manner 
similar to that employed in working up the current curves. 
The average ordinate of all runs for each condition of accelera- 
tion was obtained for each five-second interval from the start. 
These data were then used in plotting the typical pressure 
curves, which were also made to conform in their character- 
istic features to the general form of the individual curves for a 

given test. 

The Power Curves. 

The power data were obtained directly from the current and 
pressure data, values being found for each five-second interval. 
The power curves were then plotted, due consideration being 
given to the variations in current and pressure between the 
points used. The average power for a given interval of time 
was obtained by dividing the total energy for the interval by the 
elapsed time. 

The Energy Curves. 

The energy curves were obtained by integrating the power 
curves over five-second intervals, the total energy up to each 
five-second point being found in this manner. A straight line 
was then drawn from point to point, no attempt being made to 
show the variation in the energy consumption between the five- 
second intervals. The total energy readings were checked up 
with the energy data as shown by the watt-hour meter. 

The Speed Curves. 

The data for the speed curves were obtained directly from 
the speed record made by means of the "Apple" ignition gen- 
erator driven by the car axle, the pressure of which was re- 
corded on the general record by means of a Weston voltmeter. 
In working up the speed curve it was necessary to first obtain 
the actual time of start of each run. This was done by finding 
the exact instant of start with reference to the five-second score 



240 ELECTRIC RAILWAY TEST COMMISSION 

marks on the recording ammeter for the particular run, and 
transferring these data to the speed curve by means of the five- 
second scores on the latter curve. The five-second intervals 
from the start were then carefully measured, and ordinates 
erected. The various curves for each condition of accelera- 
tion were worked up in this manner, and tables compiled show- 
ing the speed for each of these runs at the various five-second 
intervals from the start. From these data, the average speed 
of all runs for a given condition of acceleration was obtained 
for each five-second interval from the start, and the typical speed 
curves were plotted. 

The Distance Curves. 

As previously stated, the instant at which the center of the 
window in the front vestibule of the car passed each pole was 
recorded on the general record. This was accomplished by 
means of an electro-magnet operating a pen. The circuit 
through the electro-magnet was closed by means of a push button, 
operated by an observer stationed in the front vestibule of the 
car. As the pole spacing was exactly 100 ft., and as the total 
distance traversed in the tests with the controller in the series 
position was approximately 1500 ft. and in the parallel posi- 
tion 2500 ft., from fifteen to twenty-five observations of the 
distance traversed with respect to the time from the start were 
accurately recorded for each run by this means. 

The exact time of start for each run was foimd by means of 
the five-second score marks on the record, and the exact instant 
at which the car passed each successive pole was determined. 
The average of these time intervals for each condition of accel- 
eration, was found by taking the average time interval of pass- 
ing each pole for all runs of the test. The distance curves were 
then plotted from the data obtained in this manner. Since 
the summation of the speed and time for a given time interval 
from the start shows the distance traversed, it is seen that the 
distance curve may be obtained by summing up or integrating 
the area under the speed curve for any time interval from the 



ACCELERATION TESTS OF AN INTERURBAN CAR 241 

start. Such integrations were made for each of the speed curves, 
and they were checked to correspond with the actual distance 
traversed up to a given instant, as shown by the distance mea- 
surements. 

The Control Data. 

The current used by the control mechanism during the period 
of acceleration was recorded on the general record. During the 
period of control this current was irregular, varying between 
2 and 3.5 amperes. A^Tien the controller reached the full par- 
allel position, the control current became constant at approxi- 
mately 3.5 amperes. The average control current during the 
test was obtained by integrating the current curves, and finding 
the average ordinate. As previously stated, this control cur- 
rent is supplied from a storage battery at a pressure of 14 volts. 
The electrical power was determined from the current and pres- 
sure data. From the measurements of time and power, the 
electrical energy dissipated in the control system could be ob- 
tained for a given interval. No attempt has been made to 
present the control data in graphical form, as they have no par- 
ticular bearing on the results of the tests, excepting in so far 
as the energy consumed by the control system is concerned. 
From the air pump calibrations of the control system were 
obtained data showing the energy per application of air for both 
the series, and the parallel operation of the controller. 

Results of the Tests. 

In the sjmopsis at the beginning of the chapter are shown in 
tabular form some of the more important mmierical results 
of the acceleration tests made upon the interurban car. The 
results are shown more completely in graphical form in Figs. 
71 to 74, inclusive. These graphical representations are shown 
on a time base, and have been divided into two sets of curves 
for each test, one set showing the electrical data, while the other 
gives the speed and distance data. The graphical records are 
accompanied by general log sheets. 



242 ELECTRIC RAILWAY TEST COMMISSION 

On the plates showing the electrical data have been plotted 
curves of pressure, current, power, and energy. The accel- 
eration curve is also placed on this sheet. On the plates show- 
ing the speed and distance, the speed is plotted in miles per 
hour and the distance traversed in feet, while the acceleration 
is plotted in miles per hour per second. Figs. 71 and 73 show 
the electrical data, while the speed and distance data are shown 
in Figs. 72 and 74. 

GENERAL LOG SHEET OF TEST NO. 18. 

Pressure. — Average line pressure, 519.1 volts. 

Distance. — Distance traversed from the start to the point 
at which the controller was at full series position, 83 ft.; dis- 
tance traversed from the start to the point at which the speed 
reached 25 miles an hour, 1510 ft. 

Time. — Interval of run from the start to the point at which 
the controller was at full series position, 9.10 seconds; interval 
of run from start to the point at which the speed reached 25 
miles an hour, 55.5 seconds. 

Acceleration. — Average acceleration for the test, 0.45 miles 
per hour per second; maximum acceleration, 1.52 miles per hour 
per second. 

Current. — Average current for the test, 204.0 amperes ; 
maximum current for the series position of the controller, 490.0 
amperes; square root of mean square current for the run, 219.7 
amperes; form factor (square root of the mean square current 
divided by the average current), 1.075. 

Power. — Average power for the test, 106.9 kilowatts; maxi- 
mum power at series position of the controller, 240.1 kilowatts. 

Energy. — Energy for the test, 1648 watt-hours; energy from 
the start to the point at which the controller was at the series 
position, 489 watt-hours. 

Controller. — Average control current for the test, 3.2 am- 
peres; average control pressure for the test, 14 volts; average 
control electrical power for the test, 44.8 watts; average time 
control current was on (2.34 seconds more than the average 



ACCELERATION TESTS OF AN INTERURBAN CAR 243 



350 



200 -3 



160 600 



CO 200 




Seconds 











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Fig, 72.— Speed and Distance Data, Test No. 18* 



200O 



1600 



244 ELECTRIC RAILWAY TEST COMMISSlOM 

time of run), 57.34 seconds; electrical energy per run to operate 
the master controller, 71 watt-hours; electrical energy per run 
taken from the line by the control circuit (based on an efficiency 
of 65 per cent for the battery and control system), 1.10 watt- 
hours; total energy per run consumed in the electro-pneumatic 
operation of the controller, 6.03 watt-hours; proportion of total 
energy taken by the car for the test, which is consumed in the 
operation of the control system, 0.37 per cent. 

Motor-compressor. — Electrical energy consumed per run 
by the motor-compressor in operating the controller (average 
for the test assuming no leakage), 0.55 watt-hour; electrical 
energy consimied per run by the motor compressor in operating 
the controller (average for the test including leakage from the 
air system), 4.93 watt-hours. 

GENERAL LOG SHEET OF TEST NO. 19. 

Pressure. — Average line pressure, 440.3 volts. 

Distance. — Distance traversed from the start to the point 
at which the controller was at full series position, 87 ft.; dis- 
tance traversed from the start to the point at which the speed 
reached 38.0 miles an hour, 2540 ft. 

Time. — Interval of run from start to the point at which the 
controller was at the series position, 9.35 seconds; interval of 
run from start to the point at which the controller was at the 
parallel position, 20.26 seconds; interval of run from start to 
the point at which the speed reached 38 miles an hour, 65.50 
seconds. 

Acceleration. — Average acceleration for the test, 0.58 miles 
per hour per second; maximum acceleration, 1.55 miles per hour 
per second. 

Current. — Average current for the test, 414.5 amperes; 
maximum current for the series position of the controller, 467.0 
amperes; maximum current for the parallel position of the con- 
troller, 623.0 amperes; square root of mean square current for 
the run, 426.3 amperes; form factor (square root of mean square 
current divided by average current), 1.03. 



ACCELERATION TESTS OF AN INTERURBAN CAR 245 

Power, — Average power for the test, 178.7 kilowatts; maxi- 
mum power at series position of the controller, 210.2 kilowatts; 



a s 

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Fig. 74. —Speed and Distance Data of Test No. 19, 



2500 



1500 



maximum power at parallel position of the controller, 236.8 

kilowatts. 

Energy. — Energy for the test, 3252 watt-hours; energy from 

the start to the point at which the controller was at the series 



246 



ELECTRIC RAILWAY TEST COMMISSION 



position, 442.6 watt-hours; energy from the start to the point 
at which the controller was at the parallel position, 1050 watt- 
hours. 

Controller. — Average control current for the test, 3.0 am- 
peres; average control pressure for the test, 14.0 volts; aver- 
age control electrical power for the test, 42.0 watts; average 
time control current was on (2.34 seconds more than the aver- 
age time of run), 67.34 seconds; electrical energy per nm to 
operate the master controller, 0.79 watt-hours; electrical energy 
per run taken from the line by the control circuit (based on an 
efficiency of 65 per cent for the battery and control system), 
1.21 watt-hours. 

Motor compressor. — Electrical energy per run consumed by 
the motor compressor in operating the controller (average for 
the test assuming no leakage), 0.55 watt-hour; electrical energy 
per run consumed by the motor-compressor in operating the 
controller (average for the test including leakage from the air 
system), 6.09 watt-hours; total energy per run consumed in 
the electro-pneumatic operation of the controller, 7.30 watt- 
hours; proportion of total energy taken by the car for the test, 
which is consumed in the operation of the controller system, 
0.37 per cent. 

Discussion of Results. 

While circumstances did not permit of as extensive a series 
of acceleration tests on the interurban car as was contemplated, 
a study of the curves given in Figs. 71 to 74 show some in- 
teresting results. 

The Pressure Curve. — As in the case of the acceleration 
tests of the single-truck car, the pressure curves show more or 
less fluctuation, due to the variation in the current taken by 
the car. In Test No. 18, where the master controller was kept 
at the series position, it will be noted that the line pressure de- 
creased considerably as soon as current was taken by the car, 
and that it became higher and higher as the current decreased 
toward the end of the nm. An inspection of the pressure curve 



ACCELERATION TESTS OF AN INTERURBAN CAR 247 

of Test No. 19, where the master controller was maintained at 
the parallel position, shows a fall in the line pressure as soon as 
the controller was turned on, an increase after the point of 
maximum current was passed for the series position, a second 
depression during the time when a large current was drawn for 
the parallel position of the controller, and a gradual rise as the 
current falls off toward the end of the run. It will also be noted 
that the line pressure is considerably more imiform for Test 
No. 18 than for Test No. 19. It should be noted in this con- 
nection that the pressure curve of Test No. 19 is shown dotted 
for the first few seconds of the test. The reason for this is that 
the original data were not complete in this particular. 

The tests were all performed during the interval between the 
passage of the cars running in regular service. Because of 
the relatively small amount of copper in the line, the proximity 
of other cars produced considerable variations in line pressure. 
The acceleration runs were so timed, however, that these varia- 
tions were reduced to a minimum during the actual time of test. 

The Current Curves. — It will be observed that the cur- 
rent curve for the series position of the master controller shows 
two very characteristic notches, while two others, somewhat 
less pronounced, are also indicated. An inspection of the cur- 
rent curves for the parallel position of the master controller 
(Test No. 19), shows this characteristic form of the current 
curve for the series position reproduced, and, in addition, there 
are clearly sho'^ni three distinct notches for the parallel points 
on the controller. The diagram of connections for this system 
of control shows nine different conditions in going from an "off" 
position of the controller to the full parallel position. The 
additional notches are not in evidence, and the probable reason 
for this is that the limit switch and the resistances have been 
so adjusted that practically no change in current occurs in pass- 
ing over the missing contacts. 

It will be observed that the maximum current for the series 
connection of the motors is practically the same for both tests, 
being approximately 475 amperes. It will also be observed 



248 ELECTRIC RAILWAY TEST COMMISSION 

that the maximum current for the parallel connection of the 
motors is considerably greater than the maximum current for 
their series connection. This is in accordance with the accel- 
eration tests of Chapter V, and is what might be expected, since 
the currents in the individual motors did not differ greatly for 
the two conditions of connection. It will also be noted that 
the maximum current for the series connection of the motors, 
is somewhat greater for Test No. 19 than for Test No. 18. It 
would be reasonable to expect that this current should be the 
same in both cases, since the controller was entirely automatic 
and the same operations were performed in each case, and in 
the same order. However, it is to be remembered that Test 
No. 19 is the result of the average of eight runs which were 
made under slightly different conditions. As previously stated, 
an attempt was made to ascertain the effect of weighing down 
the limit switch. The eight runs consisted of four different 
sets, in one of which the limit switch operated imder normal 
conditions, while in the other three weights of 0.286, 0.859, 
1.430 ounces, respectively, were placed on the limit switch. As 
these weights had such a slight effect on the controlling mechan- 
ism, the average of the eight runs was taken for the test. The 
general effect of this is the same as setting the limit switch for 
a slightly heavier current, and this is shown nicely by the fact 
that the maximum current for the series position of Test No. 19 
is somewhat larger than that shown for the same position of 
Test No. 18. 

The Power Curves. — Since the variations in pressure are 
not nearly so great as the changes in current, the power curves 
have the general characteristic shape of the current curves. 
While the maximum power is practically the same for the series 
position of the controller in each test, it is seen that the maxi- 
mum power at the parallel position is considerably greater 
than at the series position, as shown by Test No. 19. It will 
also be observed that the average power for the test is consid- 
erably less than the maximum power at the series position of 
the controller in each case. The average power for Test No. 18 



ACCELERATION TESTS OF AN INTERURBAN CAR 249 

is considerably less than that for Test No. 19, as would be ex- 
pected. Another interesting feature is shown in the compara- 
tively large fall in line pressure, due to the small amount of 
copper in the line in proportion to the large current taken by 
the car. The effect here is a relatively lower increase in the 
power taken by the car, with a given increase in the current. 
It is to be observed that, while this decrease in line pressure 
may have a tendency to prevent excessive currents being taken 
by the car during acceleration, the efficiency of the transmission 
system is considerably decreased by the large drop in the line. 

The Energy Curves. — The energy curves for the two tests 
differ somewhat in general form, and considerably in their final 
values. The energy curve for Test No. 18 shows the most rapid 
rise at the start, and a more gradual increase after the controller 
has reached the full series position. The curve for Test No. 19 
again shows a rapid rise during the period of time in which the 
controller is brought to the full series position, followed by a 
still more rapid rise as the contacts for the parallel position are 
made, and a more gradual increase from this point on to the end 
of the test. It will be noted that the total energy for Test No. 
19 is practically twice that for Test No. 18. While the time is 
nearly the same in the two cases, the distance traversed in Test 
No. 19 is approximately 66 per cent greater than in Test No. 18, 
while the speed is more than 50 per cent greater. 

The Speed Curves. — The speed curves show a rapid in- 
crease in speed at the start, which increase gradually falls off 
as the maximum speed is reached. The speed curves for both 
conditions of acceleration show smoothness and uniformity. 
No abrupt variations in speed are noticed, and from the stand- 
point of comfort to passengers, the accelerating effect is all 
that can be desired. It is to be noted that the speed rose more 
nearly to its full value for the conditions of Test No. 18 than it 
did for those of Test No. 19. The latter test would have been 
prolonged had it not been for the fact that a one per cent grade 
was encountered at a distance of 2600 ft. from the start. As it 
would have been impossible to properly interpret the various 



250 



ELECTRIC RAILWAY TEST COMMISSION 



factors after the car had passed from the level stretch of track, 
it was necessary to cut off the test before the end of this level 
portion was reached. 

The Acceleration Curves. — The acceleration curves show 
a maximum acceleration at the start, this maximum being prac- 
tically the same for both tests, and having a value of approxi- 
mately 1.5 miles per hour per second. This is what might be 
looked for, as there is no apparent reason for any variation in 
the acceleration at the start in the two tests, since the auto- 
matic action of the controller at the start was the same for both 
conditions of acceleration. The acceleration curves have the 
same general shape in the two tests, although it will be noted 
that the acceleration decreases much more rapidly in Test No. 
18 than is the case in Test No. 19. An inspection of the accel- 
eration curves with respect to the current curves will show 
that the acceleration began to fall off quite rapidly after the 
point of maximum current at the series position in Test No. 18, 
while in Test No. 19 the acceleration remained relatively high 
for a considerable interval of time after the parallel position 
of the controller was reached. 

The Distance Curves. — The distance curves all have the 
same characteristic shape, as there is comparatively little effect 
upon their general form due to slight variations in speed. The 
total distance traversed, however, is very different for the two 
tests, being 1510 ft. in Test No. 18, and 2540 ft. in Test No. 19. 



VARYING THE LIMIT SWITCH. 

As previously stated, it was the original intention to vary 
the maximum current taken by the car by so adjusting the 
limit switch that the contacts would be made under different 
conditions of maximum current. It was attempted to accom- 
plish this by means of small weights placed on the limit switch 
in such a manner as to cause greater currents to flow before 
the successive contacts were made. It was soon discovered 
that the weights used were altogether too small to accomplish 
the desired result. However, because of existing conditions, 



ACCELERATION TESTS OF AN INTERURBAN CAR 251 

time did not permit of extending the acceleration tests, and it 
was consequently impossible to obtain the results desired in 
this connection. 

While the weights used on the limit switch did not produce 
any marked effects, it was observed that there was a general 
tendency toward an increase in the current and a decrease in 
the interval during the accelerating period. 

THE CONTROL DATA. 

As shown in the data in the general logs of Tests Nos. 18 and 
19, it is seen that the energy taken in operating the control 
system is entirely negligible in comparison with the total energy 
taken by the car, it being but a fraction of one per cent of the 
latter. An inspection of the data shows that for both tests 
the energy consumed by the motor compressor due to leakage 
amounts to over seventy per cent of the total energy taken by 
the control system. It is thus seen that the amount of energy 
used in the control system, is not much greater than that which 
would be used if the air brakes and the ordinary hand controller 
were employed. 

Another feature of the electro-pneumatic system of control 
is that which concerns the time-lag between the instant at which 
the control circuit is closed, and the instant at which the motor 
circuit is closed. Measurements were made from twenty-seven 
different observations taken from the original records. The 
average of these observations showed a time-lag of 2.34 seconds 
from the instant the controller current was set up until current 
was drawn from the line. In a similar manner, the average of 
twenty-seven different observations, recording power cut off, 
taken from the original records, show no difference in the time 
intervals elapsed from the instants the control and current 
circuits were set to the instants they were cut off in the two cir- 
cuits. This demonstrates the fact that the same time-lag that 
is present in turning on the power also exists when the master 
controller is turned off. 



PART IV. 
BRAKING TESTS OF ELECTRIC CARS, 



253 



L 



CHAPTER VII. 

COMPRESSOR-STATION TESTS OF A STORAGE AIR 
SYSTEM OF BRAKING. 



Objects of the Tests. 

The principal objects of the tests were to study the char- 
acteristic features of the operation of a compressor station for 
the compressing of air for the storage system of air braking, 
and to obtain the relation between the amount of energy con- 
sumed and the volume of air compressed. The calculations 
included not only the computation of the cubic feet of free air 
compressed per kilowatt, but also computations based upon the 
actual number of cubic feet of free air delivered to the storage 
tanks on the car. 

In addition, the thermodynamic losses of the system were 
investigated, and tests were made to determine the relative 
economy of cooling by different methods. Calculations were 
also made of the energy consumed per cubic foot of free air. 

General Conditions of the Tests. 

The entire fifteen hundred cars operated by the St. Louis 
Transit Company during the summer of 1904 were equipped 
with the storage air system of braking. To supply this number 
of cars, eighteen compressor stations, located at various points 
in the city, were necessary. 

THE compressor STATION TESTED. 

The station selected for the test is located at the Tower 
Grove Park loop of the Park Avenue and Compton Avenue 
lines, operated by the St. Louis Transit Company. The general 

255 



256 



ELECTRIC RAILWAY TEST COMMISSION 



Table XXXII. 



Synopsis of Results. 

- Synopsis of Results. Station Compressor Tests. 
August 3 and ^, 1904- 



Duration of test, hours , 

Total running time of compressor, hours , 

Total number of compressor runs , 

Average interval of compressor runs, minutes , 

Average reservoir pressure, lbs. per sq. in 

Average max. reservoir pressure, lbs. per sq. in 

Average min. reservoir pressure, lbs. per sq. in 

Average range of reservoir pressure, lbs. per sq. in 

Average reservoir temperature, degrees, C 

Total volume of free air compressed, cu. ft 

Total volume of free air delivered to cars, cu. ft 

Total weight of air compressed, lbs 

Total weight of air delivered to cars, lbs 

Total weight of air lost by leakage, lbs 

Total weight of cooling water circulated, lbs 

Total heat absorbed by cooling water, B. T. U 

Average line pressure, volts 

Average current during runs, amperes 

Average current for test, amperes 

Average power during runs, kilowatts 

Average power for test, kilowatts 

Maximum power for test, kilowatts 

Total electrical energy for test, K. W. hours 

Average energy per compressor run, watt-hours 

Energy per lb. of free air compressed, watt-hours 

Energy per lb. of free air delivered to cars, watt-hours . 

Energy per cu. ft. of free air compressed, watt-hours . . . 

Energy per cu. ft. of free air delivered to cars, watt-hours 

Average number of cars in operation during test 

Average power taken by each car, kilowatts 

^ .. - power taken by compressor plant 

Ratio of 7^^ T^ , per cent . . . . . 

power taken by cars 




24.00 

9.80 

108 

5.44 

280.8 

296.9 

271.8 

25.1 

39.2 

40,402 

38,515 

3205.0 

3055.0 

150.0 

10,400 

259,295 

491.5 

46.5 

9.78 

22.85 

9.23 

26.8 

221.9 

2,052 

69.2 

12.6 

5.49 

5.76 

22 

25.3 

1.7 



2.35 
1.57 

18 

5.24 

276.2 

283.2 

256.4 

26.8 

40.8 

7,250 

6,889 

574.0 

545.5 

28.5 

4125 

6,9052 

488.0 

45.5 

29.0 

22.45 

15.0 

23.6 

35.3 

1,960 

61.5 

64.8 

4.87 

5.13 

42 

25.3 

1.4 



plan of this station is shown in Fig. 75. It contains two com- 
pressor units dehvering air into two large tanks, which are 
connected by a suitable header. The compressors are chain- 
driven by 500 volt, 50 ampere, d.c. motors, compound wound 
for constant speed, and running at 500 revolutions per minute. 
Fig. 76 shows the compressor and motor with the gear case 
removed, while another view, showing the controller, is given 
in Fig. 77. The pinion on the armature shaft carries 24 teeth. 



COMPRESSOR STATION TESTS 



257 



INSTRUMENTS 




COMPRESSOR, No.l, 



1 if^ 




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TO COMPRESSOR No.S. 




f /gr, 75. — Tbo/er firoue ParAr Station of the St. Louis Transit Company. 



258 



ELECTRIC RAILWAY TEST COMMISSION 



while the compressor gear has 99 teeth. The running parts 
of the machine are self-oihng, and the valves are all of brass 
and of poppet style. Automatic staring and stopping of the 




Fig. 76. — Station Com pressor and Motor, Showing Gear Case Removed. 

compressor are accomplished by solenoid devices in the motor 
circuit, these devices being controlled by an automatic governor, 
operated by variations in the air pressure. 




Fig. 77. —Station Compressor and Motor, Showing Controtier. 

The general scheme of station piping is also shown in Fig. 75. 
From the base of the governor, air is drawn into the low-pres- 



COMPRESSOR STATION TESTS 259 

sure cylinder, compressed to about 70 lbs. per square inch, 
forced through the inter cooler, and then into the high-pressure 
cylinder, where it is compressed to 300 lbs. per square inch. 
The cylinders are arranged in tandem. As the compressor is 
single acting, a free air space is obtained between the two pistons, 
hence no packing is used between them. As the high-pressure 
cylinder is in the end of the machine and a part of it, there is 
no packing subjected to a high pressure except the piston rings 
and the gasket under the head. A pipe from the high-pressure 
cyhnder leads to a safety valve, and to a globe valve from which 
a 2-in. riser is run into a 2 X l^-in. header, and into one of 
the tanks. The two air tanks are connected at one end by a 
2i-in. header. From the other end of the second, a pipe leads 
to a globe valve, and thence under the floor and underground 
to three hose-box valves and connections for charging cars. 
The cylinders are kept cool by circulating water through their 
water jackets, the water being supplied from a storage tank, 
one tank sufficing for two compressors. The tank is made 
of galvanized iron, about 4 ft. deep and 3 ft. in diameter, sup- 
ported with the bottom about 7^ ft. above the floor. The 
water flows from the bottom of the tank, through a pipe into 
the high-pressure cylinder jacket, through this into the inter- 
cooler, where it passes back and forth up through baffle plates, 
out and down to a pipe coil radiator exposed to the air. An 
air lift raises the water back to the tank again. This is a |-in. 
pipe connection from the intercooler to the bottom of the pipe, 
leading vertically from the radiator to the storage tank. The 
air entering the bottom of this riser acts to lift the water above 
it, causing a fairly rapid circulation. With a small valve near 
the intercooler connection, the flow of air through the lift can 
be regulated. Interconnections are made for the two machines 
so that they may both be suppHed with cooling water from the 
tank and radiator. Valves and connections are all placed so 
that the tank and radiator may be cut off and water received 
from the city water supply and drained to the sewer, after 
circulating through the jackets. The storage air system, as 



260 ELECTRIC RAILWAY TEST COMMISSION 

installed in St. Louis, is fully described in the Street Railway 
Journal, Vol. XXIII, 1904, pp. 208 and 628. 

THE CAR EQUIPMENT. 

The compressor station above described supplied air for all 
cars operating on the Compton Avenue and Park Avenue lines. 
It was not practicable to make complete tests of all of these 
cars, but the gage readings were taken on all cars, and a com- 
plete test was made upon one of the cars, which was numbered 
2600. This is the double-truck city car described in Chapter I. 
Its equipment is similar to that of 1500 other cars in service in 
the city of St. Louis. A diagram of the car piping will be found 
in Fig. 78. 

The storage reservoirs have a total capacity of about 20 cu. 
ft., and the service tank a capacity of about 2.5 cu. ft. Air 
from the storage tanks passes through the reduction valve, 
thence to the service reservoir, in which a constant gage pres- 
sure of 45 lbs. per square inch is maintained, regardless of pres- 
sure in the storage reservoir. The air passes from the service 
tank through a |-in. pipe to the engineer's valve, thence back 
again through a |-in. pipe to the brake cylinder, and the brakes 
are supplied through the usual rigging. The cars are equipped 
also with a hand brake for emergency use. The charging pipe 
for the storage tanks terminates near the middle of the car in 
a coupling head, which is denoted in the figure as " sleeve coup- 
ling." In charging the main tanks a length of flexible hose is 
used to connect the terminals of the pipe from the compressing 
station with the sleeve coupling. This pipe terminates in a 
hose-box, located close to the side of the track, and containing 
a valve for controlling the supply of air to the car. 

The packing in the brake cylinder is the ordinary leather 
packing instead of the piston rings used in steam piston packing. 
The maximum travel of the piston is about 6 inches. 

General Description of the Tests. 
The station equipment was disturbed as little as possible 
during the tests, in order that the measurements might be 



COMPRESSOR STATION TESTS 



261 



representative of the usual running conditions. The primary 
objects of the tests being to obtain the relation between the 
amount of energy consiuned and the volume of air compressed, 




KEDuciNe Valve ^; 

Sleeve CouplinGt i 

'For CHAKGrnGr /^^p=Z 5eRVICE TaN>^ 



lb Hl&H PF^ElSSURE.fA(iEgJ[: 



o 



m 



^ 



lb Service "Iani^ G/\se 



U 



To Brake Crt.. Gage. 

m 



To Cnsineer's c^ag-e 



«o 

:i 
«^ 

X 

To En<5inee.r"5 Valve. 

Fig. 78. — Diagram of Car Piping for Storage Air System of Braliing. 

the principal measurements were : (a) those relating to the elec- 
trical energy taken by the motor in operating the compressor; 
Q)) those relating to the volume and weight of air compressed, 
as deduced from measurements of pressures and temperatures 
taken before and after motor-compressor runs. 
The measurements relating to volume and weight of air com- 



262 ELECTRIC RAILWAY TEST COMMISSION 

pressed, were checked by measurements which were made upon 
the consumption of air by individual cars, as deduced from the 
measurements of the pressures and temperatures of the air in 
the tanks upon the cars before and after charging. 

The first of the compressor station tests was conducted be- 
tween 2.00 P.M. on August 3d and 2.00 p.m. on August 4th, 1904, 
measurements being made continuously over a period of twenty- 
four hours. Only one of the two compressors in the station 
was used during the tests, as it was found that the required 
pressure in the storage tanks could be readily maintained with 
one compressor, and the measurements were greatly simplified 
by making the tests under these conditions. This test was 
performed with the apparatus operating under ordinary condi- 
tions as to the circulation of cooling water, that is, with cylinder 
cooling water circulating by means of the air lift. 

The second test was made late in the afternoon of August 4th, 
after the completion of the first test. The purpose of this test 
was to determine the net saving, if any, which would result from 
a rapid circulation of cooling water directly taken from the 
city mains. The test covered a period of 2.35 hours, beginning 
at 5.10 P.M., and ending at 7.31 p.m. This part of the day was 
selected as the twenty-four-hour test showed it to be one of 
the busiest periods, considered from the standpoint of air 
taken from the compressor station by the cars. The test was 
conducted under precisely the same conditions as existed in the 
preceding test, with the exception of the manner of circulating 
the cooling water. 

As the volume of air compressed was measured by the rise in 
pressure in the storage tanks, it was essential that the com- 
pressor should not be in operation while the air tanks of the 
cars were being charged. To insure against such a contingency, 
a switch was placed in the electric control circuit, in place of the 
minimum contact point on the governor, and this switch was 
closed by one of the observers when it was desired to start the 
compressor. The compressor was run during intervals when 
cars were not drawing air from the station^ and the start of each 



, COMPRESSOR STATION TESTS 263 

run was made when the pressure in the storage tank had de- 
creased to a value near the lower limit of normal operation of 
the compressor. 

The tests consisted essentially in operating the compressor 
as frequently as was necessary to maintain the desired pressure. 
The cars were supplied with air as it was required, observations 
being made of the indications of the car gages both before and 
after each charge, in order that the amount of air taken in each 
case might be determined. The gages of all of the cars on the 
line were subsequently calibrated, in order to insure accuracy 
in the results. Blank forms were used by the observers in re- 
cording the readings of the various instruments. 

Between the twenty-four-hour test and the shorter test to 
determine the effect of a rapid circulation of cooling water direct 
from the city mains, tests were made to determine the efficiency 
of the electric motor, and also that of the compressor. The 
resistances of the armature and fields of the motor were taken, 
and a "stray power" test was made to determine the losses due 
to friction, hysteresis, and eddy currents. From these mea- 
surements, the efficiency of the electric motor was obtained. 
The electrical efficiency of the air-compressor was obtained by 
first removing the valves and then driving the compressor by 
means of the motor, the power required to drive the compressor 
being measured. 

A short test was also made covering a period of one and one- 
half hours, to determine the fluctuations of the various quantities 
involved in the compressing of air by means of the appa- 
ratus tested. The air compressor was run a number of times 
during this test, and observations were taken at very frequent 
intervals during each run. While the results of this test have 
been worked up in considerable detail, it has been found that 
the limitations of the printed report will not permit of their 
being shown graphically. The data resulting from this test 
show that the power fluctuates from a high value at the start 
through a low value, and increases toward a maximum as the 
air pressure in the storage tank rises. The total fluctuation 



264 



ELECTRIC RAILWAY TEST COMMISSION 



of the power during a run amounts to approximately 25 per 
cent after the pressure in the compressor has risen high enough 
to open the valves. Until air actually begins to enter the 
storage tank, the consumption of power averages less than 50 



CoMPR ESSOR Motor 




Wm^ 



Control Gage v / o> 

S) SNAP SWITCH 





I I I I 




STARTING 
RESISTANCE 






Smorj- 

ClRCUITING 

SW»TCH 




Metei^ 



u 



GROUND 



GROUND 

Fig. 79. — Electrical Connections for Tests of Compression Stations. 

per cent of the maximum. Less than one minute is required 
for this operation. 

ORIGINAL MEASUREMENTS. 

The principal original data obtained for the compressor 
station tests may be divided into five general classes as follows: 
(a) those relating to the electrical input; (6) those relating to 



COMPRESSOR STATION TESTS 



265 



time; (c) those relating to the speed of the motor-driven com- 
pressor, and the number of double strokes of the air compressor 
piston ; {d) those relating to the pressure of air at various points 
in the system; and (e) those relating to the temperatures of 
air and water. 

In addition, tests were made to determine the efficiency of 
the motor-compressor, and many other data were obtained, 
which either relate to the general conditions existing during 
the tests or which were' necessary in the working up of the 
results. 

Electrical Measurements. 

The electrical measurements consisted essentially in taking 
readings of the current and pressure supplied to the motor 
during the interval of run, and in reading the watt-hour meter 
at the end of each run, to obtain- the total energy delivered to 
the motor during the interval. The ammeter and voltmeter 
were read at the start and at one-minute intervals throughout 
the run in each case. 

The arrangement of instruments for the test was as shown 
in Fig. 79. A snap switch was connected in the motor governor 
circuit, so that the observer who took the electrical measure- 
ments, could prevent the compressor from starting when a car 
was taking air. The method employed in measuring the quan- 
tity of air made this necessary. 

The various electrical measurements which were made are 
shown in the following table: 



Quantity 

Measured. 



Tenninal pressure. 

Total current 

Total energy 



Instrument 
Employed. 



Weston indicating 

voltmeter. 
Weston milli-volt- 

meter with shunt. 
Thomson watt-hour 

meter. 



Method of Making 
Measurements . 



Readings at one-minute inter- 
vals throughout run. 

Readings at one-minute inter- 
vals throughout run. 

Readings at the end of each run, 
actual dial readings being re- 
corded. 



266 ELECTRIC RAILWAY TEST COMMISSION 

Time Measurements. 

The time of start and stop of each run was accurately re- 
corded from observations made from a watch. From these 
data, the time interval of each run was found. 

Speed Measurements. 

The speed of the motor was obtained by means of a speed 
counter and watch. From these measurements the number 
of revolutions of the motor armature per minute was obtained, 
and from this value the number of strokes of the compressor 
piston was deduced. 

Pressure Measurements. 

In order to determine the volume of air delivered to the 
storage tanks, it was necessary to make accurate determina- 
tions of the pressures and temperatures at various points in 
the system. The air pressures in the main tanks, in the inter- 
cooler, in the main pipe line, and in the cars were measured upon 
reliable gages which were checked from time to time. These 
readings were taken before and after each run, or before and 
after a car received a charge of air. 

Temperature Measurements. 
Calibrated quick reading thermometers were placed so as to 
obtain the various temperatures as follows: 

(1) Air intake; 

(2) Intercooler; 

(3) Discharge pipe; 

(4) Interior of tanks; 

(5) Exterior of tanks, both near the top and near the bottom ; 

(6) Hose-box pipe; 

(7) Room temperature, both near the ceiling and near the 

floor; 

(8) Temperature of the outside air. ' 
To obtain temperatures 2, 3, and 6 it was necessary to insert 

thermometers in specially constructed oil wells. It was found 
impracticable to use a built-up oil well, because of the exces- 



COMPRESSOR STATION TESTS 267 

sively high temperatures. These oil wells were each made of 
one piece of steel. Temperature readings were made at fre- 
quent intervals throughout each run. 

Measurements of Cooling Water. 

In order to accurately determine the amount of cooling water, 
two supply tanks were used, the second one being installed ex- 
pressly for the purpose of the tests. These were connected by 
piping and valves, and were so arranged that the water could 
be delivered to the compressor from the tanks alternately, one 
tank being filled w^hile the other was being discharged. By 
observing the rise and fall of the level of the water in the tanks, 
the volume of water was accurately determined. The arrange- 
ment of the tanks and the piping is shown in Fig. 75. 

In all of these measurements, the readings of the instrimients 
were taken before and after each compressor run, before and 
after charging each car, and at such other times as would in- 
sure accuracy in the work. At times when the demand for air 
was small, as during the night, the readings w^ere taken at 

regular intervals. 

Calibration of Car Gages. 

In order to determine the amount of air delivered to the cars 
during the twenty-four-hour test of the Park Avenue station, it 
was necessary to calibrate the gages of all of the fifty-four cars 
then in service on this line. This was done in the following 
manner. 

The small calibrating outfit shoT\Ti in Fig. 80 was connected 
to one of the hose-boxes near the compressor station. E is the 
main hose-box valve, from which a pipe was led out to the tank 
A, the latter being filled with bleeding cock D. By manipula- 
tion of these valves, any desired pressure up to the limit of the 
station, could be obtained in the tank. Ten extra car gages were 
taken to the station, and as each car pulled up, its gage was 
quickly removed and temporarily replaced with another. Each 
gage was then compared with the standard at such pressure as 
corresponded to the readings which were taken during the 



268 



ELECTRIC RAILWAY TEST COMMISSION 



twenty-four-hour run. Since a record of each car throughout 
this time had been accurately kept, it was a simple matter to 
enter the corrected readings without the laborious task of 
plotting calibration curves. The results of the calibration 
showed that enough gages were in error to have materially 
affected the results, had not this precaution been observed. 

Determination of Losses. 

The losses occurring in the system may be classified as fol- 
lows: (1) motor losses, both electrical and mechanical; (2) com- 
pressor losses, mechanical; (3) heat losses to the air both during 



k= 






1 


1 








A 


5t/<noar^ 
G-Ase 






J 


K 


Car 








e. 






—f — 






) 


"— t 











Fig. 80. — Connection for Calibrating Car Gages. 

and after compression; and (4) actual losses of air, both by 
leakage and in the "air-lift," which was used for circulating 
the cooling water. These losses all affect the efficiency of the 
system, and for the purposes of this test they were separated 
as far as practicable. 

Methods Employed for Determining Losses. 
Motor Efficiency. — In order to secure the necessary data 
for determining the motor efficiency at various loads, measure- 
ments of the resistance of the series and shunt fields were made 



COMPRESSOR STATION TESTS 



269 



at working temperatures. The motor was then operated with- 
out load at normal speed by exciting the field to full-load 
strength by means of current sent through the series field, the 
connections for this test being as shown in Fig. 81. Measure- 
ments of the electrical power input with the motor operating 
under these conditions, give a means for ascertaining the core 



TROLLEY 




WATT 
HOUR 

Meter, 



CROUNO 



GROUND 
Fig. 81 . — Connection for Electrical Measurements of Motor Losses. 

losses and friction, which for the purposes of this test may be 
considered constant as the load varies, assuming the speed to 
remain the same. 

Compressor Efficiency. — The mechanical efficiency of the 
compressor was determined by removing the air valves and 
running it "light," the electrical input of the motor being 
determined at the same time. 



270 ELECTRIC RAILWAY TEST COMMISSION 

Heat Losses from the Air. — In order to ascertain the 
manner in which the heat energy was hberated from the air 
during and after compression, the system was divided up into 
a number of sections, and the temperature of the air was mea- 
sured as it entered and as it left each section. In addition, 
the amount of water circulated about the cylinders and the 
intercooler, and the temperatures of the same were carefully 
determined so that the amomit of heat removed could be cal- 
culated. A special test was conducted to determine the effect, 
upon the system, of a more rapid carrying away of the heat 
from the compressor than that which was in ordinary use in 
the station. 

Measurements of Air Lift. — A separate test was necessary 
for this purpose. The plan used was to deliver the air from 
the lift into an inverted measuring vessel in one of the large 
tanks, the vessel being first filled with water. The time neces- 
sary for the air from the lift to fill this vessel was determined. 

In determining the actual amount of air compressed it is 
necessary to know the pressures and temperatures before and 
after compression, and also the volume of the receiver into 
which the air is pumped. Having obtained these quantities, it 
remains to reduce them to standard conditions in order that 
the results obtained may be comparable with those of other 
tests. The measurements are changed in accordance with the 
laws of perfect gases, to correspond with a temperature of zero 
degrees centigrade and an absolute pressure of fifteen pounds 
per square inch. The results show, therefore, the amiount of 
electrical energy required to compress a cubic foot of free air 
at a barometer pressure of fifteen pounds per square inch, to 
a given gage pressure at 0° C. 

The following convenient formulae have been used in these 
calculations : 
Symbols. 

Pj = Absolute pressure in storage tanks before a compressor 

run. 
Pg = Absolute pressure in storage tanks after a compressor 
run. 



COMPRESSOR STATION TESTS 271 

iPj = Absolute temperature in storage tanks before a com- 
pressor rim. 
7^2 = Absolute temperature in storage tanks after a com- 
pressor run. 
Fj = Volume of free air in storage tanks before a compressor 

run. 
Fj = Volume of free air in storage tanks after a compressor 
Tun. 
K, K^ = Reduction constants. 

t^ = Temperature by thermometer before a compressor run. 
^2 = Temperature by thermometer after a compressor run. 

All of the above symbols relate to the several quantities as 
actually measured. To represent the same quantities reduced 
to standard conditions, that is, 0° C, and fifteen pounds per 
square inch absolute pressure, the following corresponding 
symbols are employed: 

P\, P\, T\, T\, V\, V\, t\, and t\. 
0° C. is taken as 273° C. absolute temperature. 

Fj = F2 ^ cubic feet in tanks and piping. Then, according 
to the thermodynamic law of perfect gases, 

P V -= K T 

Dividing and solving for volume under standard conditions, 

P T 

y = £jL X -— ' X F 

^ 1 ^ 1 



Likewise, 



15 273 + t^ ' 273 + ^ 

P 

F' — K Y ^ . 

^'-^^ 273 + t: 



Then the standard volume delivered to the storage tanks 
during the run under consideration will be 

r = v\ - v\. 



272 



ELECTRIC RAILWAY TEST COMMISSION 



WORKING UP THE RESULTS. 

The data sheets were first bound into books, and such cor- 
rections as the caHbrations showed to be necessary were entered 
therein. The next step consisted in assembhng the data for 
the test on one large sheet, called for convenience the "com- 
bined log sheet." This large sheet contained spaces for all 
calculations, and as it formed an essential part of the work, 
and also because it shows in condensed form the nature of the 
calculations, the headings of the many columns of this sheet 
are inserted in this report. None of the actual readings are 
included, as they nmiiber many thousands and as they are 
incorporated into the diagrams which show graphically all of 
the results of the tests. The readings of the combined log 
sheets, with explanatory notes, are as follows : 



Time. 


Power. 


Speed. 








1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


c 

O 
S 


a 

U O 

cog 

°a 

Bo 
H 


Time of Stopping 
Compressor. 


"S 

p^a 

< 


03 

a 0) 
J" 


02 

>s 


ar>-< 

oj X 


OJ 

.a 

t, X 

o . 

-? > 
ax 

> 


as' 


u 
o 

O 

'o 




si 

03 a 

PS 



No. of Instrument. 



Notes on the Various Items. 

Column 1. — A run was covered between the time at which 
the compressor was allowed to start and that at which it was 
stopped by the controller, operated by the tank pressure. 

Column 2. — The compressor was started by hand when the 
tank pressure had fallen through the normal range and when 



COMPRESSOR STATION TESTS 273 

no car was taking air. This precaution was necessary in order 
to avoid error in measuring the amount of air compressed. 

Column 3. — The compressor motor was stopped automatic 
call}- by means of the controller when the tank pressiu*e reached 
the upper limit. 

Column 4. — This quantity is the interval between the times 
recorded in the preceding two columns. 

Columns 5 and 6. — By taking frequent readings the ob- 
servers averaged the current and electromotive force during a 
run, and these readings were afterward corrected by calibration. 

Column 7. — The average power during each run was ob- 
tained by multiplying together the readings of Columns 5 and 6. 

Column 8. — The total electrical energy absorbed per run 
was calculated by multiplying together the watts as in Column 
7 and the time as in Column 4. 

CoLuiMN 9. — An integrating watt-hour meter was employed 
in order to check the results obtained in Column 8. 

CoLuiMN 10. — The speed of the motor was determined by 
means of a revolution counter attached to the motor shaft. 
The times of starting and stopping were noted, as were also the 
coimter readings before and after each rim. 

Column 11. — As the motor and compressor were geared by 
a chain drive, the compressor revolutions were deduced from 
Colimin 10 by multiplying the motor revolutions by the gear 
ratio. 

Column 12. — This item was obtained by dividing the strokes 
by the time-interval of the run. 



274 



ELECTRIC RAILWAY TEST COMMISSION 



Air. 



Temperatures, Degrees Centigrade. 



13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


24 


25 


a 6 


a>.S > 






-irf . 


_^? 




'^ . 


^? 


.S 
«-~^ d 






d 
o 


O t> 


Th 

Well 
p-Val 


o a 




cs a 
^5 


s o 
J- 
H o 




cs a 
HO 


GO 

Si 




d' 
^ o 


d 
o 


6 o 


»5^ 




^-Q 






'^■^ 


. . <i>'d 


'-< o 




0:=) 


o c 


O tH 

it 






Hose-Box 
bermomet 
lug) Car C 


CO 


CO 


-a 




a; o « 

«2^ 


;- W 


(^ 0) 


M 


m ^-^ 


c3 0} 


»j 


rcv^ 


d 


d 


on 




^£ 


"5^ 

O^ 


3- 

On 


^£ 


'^4 


Oo 


1— 1 


(—1 


o 




hH P^ 








^ 






^ 


b^ 









No. of Instrument. 





01 




<D 




01 




<D 




0> 




(0 




d) 




01 


he 










t-l 




^ 




u 




L^ 




!-. 




I-, 


;^ 


14 




^ 


(J 




a 






o 


0) 


O 


CIJ 


u 


01 


u 


Oi 


o 


a> 


o 


01 


,o 


0) 


J^ 




<D 


^ 








■+J 




































o 


t*-l 


(U 


M-l 


0) 




(U 




Oi 




01 


t4-l 


0) 




4; 






o 


a 




W 


^ 


« 


<5 


pq 


< 


W 


<1 


W 


< 


« 


<J 


m 


<J 


w 


« 


<1 


« 


P 



These temperature readings were made for two purposes; to 
use in connecting the vokime of the compressed air for tempera- 
ture, and to show the losses in heat in different parts of the 
system. 

Column 13. — This item shows the temperature of the air 
entering the compressor. 

Column 14. — The compression was in two stages, and this 
temperature was taken in the cooHng receiver between the two 
cyhnders. 

Column 15. — The discharge pipe connects the compressor 
with the storage tanks. 

Columns 16, 17, and 18. — These temperatures were taken 
in order to obtain an average temperature in the storage tank. 
In Cohimn 16 the readings are obtained by placing the ther- 
mometer in an oil well tapped into the bank wall. The other 
temperatures were obtained by laying thermometers against 
the tank wall, and covering them with non-conducting material. 

Columns 19, 20, and 21. — These show the same items for the 
second tank. The air passed first into tank No. 1, and then into 
tank No. 2. 



COMPRESSOR STATION TESTS 



275 



Column 22. — This measurement was made to show the 
temperature at which the air entered the cars, in order to be able 
to calculate from the volume of the car tanks the amount of air 
received by the cars. 

Columns 23, 24, and 25. — These were obtained to show tem- 
peratures in which the apparatus operated. The first was on the 
level of the storage tanks, the second on that of the compressors 
and motors, and the third on that of the car equipment. 



AlK. 



Pressure, Lbs. per Sq. In. 


Vol. Cu. Ft. at 0° C. and 14.7 Lbs. Bar. Pressure. 


26 


27 


28 


29 


30 


31 


32 


33 


34 


35 




6 
a 

X 

o 

m 

o 
M 


<D 

o 
o 
u 
a> 

a 
1— 1 


S M 


03 


-^3 

CO 


o . 

O m 

^£ 

o ,, 


^ G 
o3 01 

^1 


03 

tn-H 

^ a 
o 

d 


a 

C 

03 

-.^ 

> 













No. 


3f Instrument. 










V 






i) 


















M 


tH 




u 


(i 
















o 


o; 




O 


O 


















..J 














































m 


< 




ffl 


<lj 

















A^o^es 0^1 ^/ze Various Items. 

Column 26. — The tank pressures before and after each run 
were obtained for the purpose of calculating the amount of air 
compressed. 

Column 27. — The hose-box pressure was found in order to 
determine the loss in pressure in the piping system, and as a 
check upon the other measurements. 

Column 28. — The intercooler pressure indicates the distribu- 
tion of the work of compression between the two cylinders of 
the compressor. 

Columns 29 and 30. — The air in the tanks at any time was 
calculated from the pressure and temperature of the air. The 



276 



ELECTRIC RAILWAY TEST COMMISSION 



volumes of the tanks and piping were accurately obtained, and 
correction was made for the water condensed in the tanks. In 
referring to the amount of air it is to be understood that this 
is free air at 0° C and 14.7 lbs. barometric pressure. 

Column 31. — This quantity is the difference between those 
in the preceding two columns. 

Column 32. — The theoretical amount of air compressed 
is that corresponding to the piston displacement. 

Column 33. — This volume was drawn by the cars and lost 
by leakage, and it was measured by the reduction in pressure. 

Column 34. — A careful count of the cars which were charged 
was kept, and their individual numbers were recorded. 

Column 35. — This volume was measured by noting the rise 
in pressure in the car tanks. The individual car gages were 
all calibrated. 



Water. 



36 



Temperature in Deg. Cent. 



37 



o 

C 



38 



73 

a 

03 



39 



MO 



40 



o3o 

rG t-, 

hC3 

tCj CO 

CPh 1/3 
<D ^ CD 

ffl 



41 



42 



Temperature Differences, 
Deg. Cent. 



43 



> (h 

<a CO 

r- 1 Qj 

o3-C t; 
be 0) 



44 



h^ CO 
0) 

C 1 
cS fe t^' 

■S s 
■g.So 



45 



> 

03 . 

O 

T) O 

c « 
Cm 



46 



> . 

a ^ 

Mo3 

II 



47 



c| 

■n bf) 

<x> a 

CI 



No. of Instrument. 


q; 




<0 




4) 




m 




01 




<D 




0) 




0) 




(D 




<u 




<p 




dJ 






(- 


tH 


b4 


b 


tH 


^ 


d 




;.! 


U 


^.4 


L. 


u 


(h 


^ 


(H 


ti 


(h 


t, 


tH 


u 




^ 


u 


Cl) 




aj 


C 


(1) 


o 


S 


o 


a; 


O 


<u 


o 


fl) 


o 


01 


o 


0) 


o 


01 


o 


(D 




0) 




-tj 




-*i 












































t+- 








^4-1 




<4-C 








m 








tw 




<<-l 








«« 




«M 


m 


< 


ffl 


<t5 


PQ 


< 


Ph 


<1 


« 


<i 


PQ 


<! 


pq 


<^ 


m 


<5 


m 


< 


P5 


<1 


pq 


< 


pq 


<J 



The measurement of the heat losses in the cooling water was 
made in order to allow a separation of the various heat losses 
in the system. Oil wells were inserted in the piping at the proper 
points, in order to obtain the exact temperature of the water. 



COMPRESSOR STATION TESTS 



277 



Columns 36 and 37. — The temperatures in the water mea- 
suring tanks were important items, as these were a measure of 
the efficacy of the coohng radiator, located between the tanks 
and the compressor. 

Columns 38 to 42. — These temperatures indicate the amount 
of radiation in the different parts of the system. 

Columns 43 to 47. — These quantities are obtained by noting 
the difference between temperatures of the water entering and 
leaving the different important sections of the system. 



Water. 



Height and Flow. 



48 






49 


50 


51 


52 


53 


54 


-uT 


C2 


+i 








J3 




A 




w 




bC 




bC 




-D 


C3 


•Si 




.Sz 






15 


%^ 


"c^ 


s-^ 


^ 3 


o^ 


"o^ 




c 


It 


O 






SCI 




5tl 




O 


P 


c 




H 





55 






No. of lostniment. 


c 






0) 














;h 






L4 














O 


0) 




o 


<u 
































0) 






(1> 














CQ 


< 




pq 


■< 













The amoimt of water circulated around the parts of the com- 
pressor was determined by means of two tanks used alternately, 
the heights of the levers being determined before and after each 
run. 

Columns 48 to 51. — These measurements were made by 
means of floats which operated pointers traveling over scales. 

Columns 52 and 53. — These were obtained from the areas 
of the tanks and the changes in areas, the height of water being 
taken from the density at the average temperature. 



278 



ELECTRIC RAILWAY TEST COMMISSION 



Column 54. — These items were obtained by dividing those 
of Column 53 by the time of each run. 

Column 55. — In order to compare this plan of cooling with 
others, the total amount of heat conveyed from the air by the 
water makes a satisfactory quantity for measurement. The 
heat per run is therefore tabulated. 

Results of the Tests. 
It was the original intention to represent all of the results 



i 




































- 




S 








































1 




































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a 
































/ 








^ 


^_ 


























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^ 




























y 


__ 
















Pot 


er 
















r^ 


/ 










^1 


























y 




























— 1 








n 


/ 




















21000 
















LP 


/f 




































r^ 


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r- 


1 1— 1 








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50 


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1 








































K 


p- 


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■t 


_- 


( 


xirre 


it 








P 


— if 


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[— 1 




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r 




































40. 




II 





































5:00 P.M. 5:30 6:00 6:30 7;00 

Fig. 82. — General Electrical Data of Test No. 21. 



7-.30 



of the compressor station tests in graphical form. It was 
found, however, that the limitations of the report would not 
permit of such a large number of curve sheets for a single chap- 
ter. The general and detailed results have, therefore, been put 
into the form of tables. 

Although it has been found impracticable to insert, in the 
final report, curve sheets showing the various data in graphical 
form, such graphical logs were prepared from the original data 
and were used in working up the results shown in the various 



COMPRESSOR STATION TESTS 



279 



tables. In order to illustrate the relation between these graph- 
ical logs and the tables contained in the report, two charts 
have been prepared, which are shown in Figs. 82 and 83. These 
plates show the relation between the results obtained from the 
air compressor and the electrical quantities entering into the 
operation of the motor which drives the compressor. These 
two charts were prepared from the data of the 2.35-hour test. 



300 6000 



aoo 4000 



100 2000 



















































A 


Total 


Volui 


leCo 


mpre 


jsed 


































B 


rolui 


leln 


Stora 


;e Reservo 


Ira 
































C 


V^olui 


leCo 


upre 


isedper £ 


W.-l 


lour 












































































































> 


'A 






































/ 




/ 
























i 


i 












J 


/ 






























i.. 










/ 


r^ 
































'"1 
1 






/ 


y 


















> 


^ 


r 




\ 


A 










1 


')/■ 


r^ 


/\ 


A . 


^ V 


/ 


k 


/ 


rB 






/ 




'•^ 


V 

1 


\ 


1 


\y 


\(V 


\, 


la 


y 


V 


tv 


V 

r 


> 


iV 


** 


\ 


(/ 


-c 












I 


J 


t^ 




y 


V 


/ 


/ 












r— 


* 






















\ 


1 


/ 


/ 












1 


I 
1 
























l- 


y 


r-' 










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f 


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Time 5:00 P.M. 6:30 6KX) 6:30 7.00 

Fig. 83. — General Air Data of Test No. 21. 



Table XXXIII shows the air temperature of the twenty- 
four-hour test and Table XXXIV shows the temperature of 
the cooling water, while Table XXXV gives a general summary 
of this test. The more general results of the twenty-four-hour 
run are shown in Table XXXVI. 

In Table XXXVII are shown the temperature data of the 
2.35-hour test, compared with the similar data taken from an 
equal interval of time for the same period of the day. 

In a similar manner, Table XXXVIII shows a general sum- 



280 



ELECTRIC RAILWAY TEST COMMISSION 



mary of the two tests arranged for comparison by considering 
a 2.35 hour period in the twenty-four-hour test. In Table 
XXXIX are given the more general data for the two tests, 
similar 2.35-hour periods being chosen. 



Table XXXIII. — Average Air Temperatures by Three-Hour Periods} 

TWENTY-FoUR-HoUR RuN. 



Period. 



Temp, at intake 

Temp, in intercooler 

Temp, in discharge pipe of 

compressor. 
Temp, in storage tank No. 1. 

Temp, in storage tank No. 2. 

Rooni temp, near ceiling . . 

Room temp, near floor .... 

Temp, at hose-box 

Temp, of outdoor air 



2-5 


5-8 


8-11 


11-2 


2-5 


5-8 


8-11 


11-2 


P.M. 


P.M. 


P.M. 


A.M. 


A.M. 


A.M. 


A.M. 


P.M. 


29.5 


29.5 


27.6 


27.4 


26.5 


25.7 


27.9 


30.2 


85 


85 


82 


81 


80 


78 


82 


86 


47.1 


54.5 


52.5 


47.8 


42.6 


46.6 


54.8 


53.8 


117 


130 


127 


118 


109 


116 


131 


129 


102.0 


119.7 


110.5 


91.5 


56.5 


102.6 


116.9 


108.5 


216 


247 


231 


147 


134 


216 


242 


227 


46.9 


51.1 


47.3 


40.7 


31.6 


36.0 


46.6 


45.4 


116 


124 


117 


105 


89 


97 


116 


114 


39.0 


39.9 


38.2 


34.5 


30.1 


29.1 


34.1 


36.3 


102 


104 


101 


94 


86 


84 


93 


97 


37.5 


36.8 


34.0 


30.6 


27.3 


27.9 


33.2 


36.3 


99 


98 


93 


87 


81 


82 


92 


97 


31.9 


30.7 


27.2 


25.0 


22.7 


24.5 


24.7 


32.8 


89 


87 


81 


77 


73 


75 


76 


91 


26.6 


26.8 


24.9 


22.8 


19.7 


22.3 


24.1 


28.0 


80 


80 


77 


73 


67 


72 


75 


82 


28.8 


25.0 


19.3 


17.3 


15.8 


20.6 


26.7 


31.1 


84 


77 


67 


63 


60 


69 


80 


88 



Average 
FOR En- 
tire Run 



28.4 

83 

50.6 
123 
101.1 
214 

43.2 
110 

35.2 

95 

33.0 

91 

27.4 

81 

24.4 

76 

23 

74 



Note. — Each temperature is shown in both Centigrade and Fahrenheit degrees, the 
Centigrade values being given first. 



Table XXXIV. — Average Temperatures , of Cooling Water by Three-Hour 

Periods. 

TwENTY-FoUR-HoUR RuN.* 





2-5 


5-8 


8-11 


11-2 


2-5 


5-8 


8-11 


11-2 


Average 

FOR En- 




P.M. 


P.M. 


P.M. 


A.M. 


A.M. 


A.M. 


A.M. 


P.M. 


tire Run. 


Temp, in water tank No. 1 


37.8 


43.9 


44.6 


42.2 


38.6 


38.5 


43.7 


46.1 


41.9 




100 


111 


112 


108 


102 


101 


111 


115 


107 ] 


Temp, in water tank No. 2 . 


39.0 


45.6 


45.5 


43.3 


40.2 


37.9 


44.8 


46.2 


42.8 




102 


114 


114 


110 


104 


100 


113 


115 


109 


Temp, water entering high- 


33.4 


37.1 


34.7 


33.6 


26.6 


31.1 


37.3 


39.4 


34.1 


pressure cylinder jacket. 


92 


99 


94 


93 


80 


88 


99 


103 


93 


Temp, water between cylin- 


37.6 


40.6 


41.2 


39.0 


32.4 


34.2 


41.4 


22.8 


38.9 1 


ders. 


100 


105 


106 


102 


90 


94 


107 


113 


102 ;I 


Temp, water entering inter- 


41.7 


46.8 


45.7 


44.2 


36.2 


39.0 


47.5 


49.3 


43.8 


cooler. 


107 


116 


114 


112 


97 


102 


118 


121 


111 


Temp, water leaving inter- 


45.5 


51.2 


49.8 


48.2 


40.3 


43.2 


52.2 


53.0 


47.9 


cooler. 


114 


124 


122 


119 


105 


110 


126 


127 


118 


Temp, water leaving radi- 


38.3 


44.3 


44.2 


39.4 


33.4 


36.8 


43.4 


45.2 


40 . 7 ! 


ator. 


101 


112 


112 


103 


92 


98 


110 


113 


105 , 



* Each temperature is shown in Fahrenheit and in Centigrade degrees, the Centigrade 
values being given first. 



COMPRESSOR STATION TESTS 



281 



Table XXXV. — General Summary by Three-Hour Periods. 

TWENTY-FoUR-HoUR RuN. 



Period. 


2-5 


5-8 


8-11 


11-2 


2-5 


5-8 


8-11 


11-2 


Totals 
FOR En- 




P.M. 


P.M. 


P.M. 


A.M. 


A.M. 


A.M. 


A.M. 


P.M. 


tire Run. 


Item No. 1, total vol. of free 


5,870 


7,470 


6,170 


2,730 


896 


6,880 


6,400 


3,987 


40,402 


air compressed in cu. ft. 




















Item No. 2, total vol. of free 


5,750 


6,910 


5,120 


2,100 


415 


7,210 


6,280 


4,730 


38,515 


air used by cars in cu. ft. 




















Item No. 3, total vol. of 


17.0 


3.50 


18.0 


11.5 


6.0 


32.0 


25.5 


23.56 


168.36 


cooling water circulated 




















in cu. ft. 




















Item No. 4, B. T U. ab- 


7,920 


13,740 


8,220 


7,030 


3,950 


11,200 


11,800 


9,940 


73,800 


sorbed by cooling water 




















in the H. P. cylinder. 




















Item No. 5, B. T. U. ab- 


8,020 


24,160 


9,120 


6,645 


2,580 


17,400 


17,530 


11,820 


97,275 


sorbed by cooling water 




















in the L. P. cylinder. 




















Item No. 6, B. T. U. ab- 


7,150 


17,300 


13,020 


5,240 


2,740 


15,070 


13,500 


14,200 


88,220 


sorbed by cooling water 




















in the intercooler. 




















Item No. 7, B. T. U. ab- 


23,090 


55,200 


30,360 


18,915 


9,270 


43,670 


42,830 


35,960 


259,295 


sorbed by cooling water 




















(total). 




















Item No. 8, kilowatt -hours 


32.3 


39.6 


27.9 


15.1 


5.7 


37.5 


35.6 


28.2 


221.9 


furnished motor (total). 




















Item No.' 9, actual running 


M S 


M S 


M S 


M S 


M S 


M S 


M S 


M S 


M S 


time of motor-hours. 


88 15 


110 32 


77 10 


42 


13 15 


97 15 


90 


69 40 


588 7 




1.47 


1.84 


1.28 


0.70 


.22 


1.62 


1.50 


1.16 


9.80 


Item No. 10, average kilo- 


21.9 


21.4 


21.6 


21.4 


25.3 


23.1 


23.6 


24.8 


22.8 


watts furnished motor. 




















Item No. 11, average tank 


285 


279 


276 


289 


286 


284 


288 


288 


280.8 


pressure in lbs. per sq. in. 




















tank No. 2. 





















Table XXXVI. — General Results of Twenty-Four-Hour Run. 



Total volume of free air compressed to 280.8 lbs. gage 

pressure. 

Total electrical energy absorbed 

Electrical energy absorbed per 1,000 cu. ft. of free air 

compressed. 
Volume of free air compressed per k. w. hour absorbed 
Electrical energy absorbed per pound of free air 

compressed. 
Weight of free air compressed per k. w. hour absorbed 



40,403 cu. ft. 

221.9 k.w. hours. 
5 . 49 k. w. hours. 

182.0 cu. ft. 
69 . 2 watt-hours. 

14.5 lbs. 



282 



ELECTRIC RAILWAY TEST COMMISSION 



Table XXXVII. — Showing Average Temperatures for Test No. 21 compared 
with those for a Similar Period in Test No. 20. 

Air Temperatures. 



System of Cooling Employed. 


Test No. 20. 
Water Cir- 
culated BY 
Air Lift, 


Test No. 21. 
City Water. 


Temperature at intake 


29.5 

85 


26.7 




80 


Temperature in intercooler 


54.5 
130 


42.8 




109 


Temperature in compressor discharge pipe 


119.7 

247 


107.4 
225 


Teniperature in storage tank No. 1 


51.1 
124 


45.3 




114 


Temperature in storage tank No. 2 


39.9 
104 


36.3 




97 


Room temperature near ceiling 


36.8 
98 


33 




92 


Room temperature near floor 


30.7 

87 


27.2 




81 



Water Temperatures. 



Temperature in water tank No. 1 


43.9 
111 


32.1 




90 


Temperature in water tank No. 2 


45.6 
114 


31.8 




89 


Temperature of water entering h. p. cylinder 
jacket. 


37.1 
99 


22.7 
73 


Temperature of water between cylinders 


40.6 
105 


24.6 
76 


Temperature of water entering intercooler 


46.8 
116 


22.8 
83 


Temperature of water leaving intercooler 


51.2 
124 


32.0 
90 



COMPRESSOR STATION TESTS 



283 



Table XXXVIII. — General Summary of 2.35-Hour Run with City Water, 
Arranged for Comparison with Twenty-Four-Hour Run. 

(These periods are on consecutive days and conditions are entirely similar.) 





Aug. 3. 


Aug. 4. 




2.35 Hours, 


2.35 Hours, 




BETWEEN 


BETWEEN 




5 AND 8 P.M. 


5 AND 8 P.M. 


Item No. 1. — Total volume of free air com- 


6,135 


7,250 


pressed in cu. ft. 






Item No. 2. — Total volume of free air used b}' 


5,420 


6,889 


cars in cu. ft. 






Item No. 3. — Total weight of cooling water 


1,699 


4,125 


circulated in cu. ft. 






Item No. 4. — B, T. U. absorbed by cooling 


10,750 


14,107 


water, H. P. cylinder. 






Item No. 5. — B. T. U. absorbed by cooling 


18,910 


28,947 


water in L. P. cylinder. 






Item No. 6. — B. T. U. absorbed by cooling 


13,540 


25,998 


water in intercooler. 






Item No. 7. — B. T. U. absorbed by cooling 


43,200 


69,052 


water, total. 






Item No. 8. — Kilowatt-hours furnished motor. 


31.0 


35.3 


total. 






Item No. 9. — Actual running time of motor. 


1.44 


1.57 


hours. 






Item No. 10. — Average kilowatts furnished 


21.4 


22.45 


motor. 






Item No. 11. — Average tank pressure in lbs. 


279.0 


276.2 


per sq. in. in tank No. 2, 







Table XXXIX. — General Comparison to Show Relative Merits of the Two 
Systems of Cooling the Air During Compression. 





Aug. 3. 


Aug. 4. 




2.35 Hours, 


2.35 Hours, 




BETWEEN 


BETWEEN 




5 AND 8 P.M. 


5 AND 8 P.M. 


Item No. 1. — Rate of flow of cooling water in 


.1944 


.471 


cu. ft. per minute. 






Item No. 2. — Total weight of air compressed, 


468 


574 


in lbs. 






Item No. 3. — Watt-hours delivered to motor 


66.2 


61.5 


per pound of air compressed. 






Item No. 4. — Motor efficiency (per cent) 


88.3 


88.2 


Item No. 5. — Compressor efficiency (per cent) . . 


88.3 


88.1 


Item No. 5. — Watt-hours actually delivered to 


51.6 


47.9 


air per pound compressed. 







284 ELECTRIC RAILWAY TEST COMMISSION 

■* 

Discussion of Results. 

In the discussion, the more general results will be first con- 
sidered, and this will be followed by a discussion of the results 
in detail. While a number of tables are given showing the 
results in detail, the more general data have been assembled in 
the synopsis at the beginning of the chapter. 

General Results. — In Table XXXII the general results 
of Tests Nos. 20 and 21 are presented, not by way of compari- 
son, but to give in compact form the most important data for 
reference. A correct comparison of the results of the rmis 
made with different methods of cylinder cooling, requires the 
study of similar periods in the two tests. Such a comparison 
is made in Table XXXVIII. 

The primary object of these tests was not to compare the 
two systems of cooling, but to determine the energy needed 
to supply compressed air for operating electric car brakes. 
Table XXXII, therefore, should be viewed from this stand- 
point. 

The first test shows the average conditions of operation for 
an entire day and night, while the conditions during the heavi- 
est part of the day are shown in the second test. The compres- 
sor under test supplied the entire quantity of air needed for 
braking on the Park Avenue line, as many as fifty-four double 
truck cars being operated at one time during the rush hours. 
These cars averaged twenty tons in weight, including passen- 
gers. The number of car miles run in Test No. 20 was 4608, 
and in Test No. 21, 863. During the period covered by Test 
No. 21, the compressor was working nearly up to its capacity, 
which latter would have been reached when continuous opera- 
tion became necessary. Obviously, however, it is essential that 
a reserve be provided, and the results show that one com- 
pressor has sufficient capacity to supply the entire fine. The 
station contains an additional compressor as an extra pre- 
caution against breakdown. It will be noted that during the 
entire day the running time was 9.80 hours, or 41 per cent of 



COMPRESSOR STATION TESTS 285 

the time. During the period of heavy load covered by Test 
No. 21, the actual running time was 67 per cent of the total 
time. 

This difference is further indicated by the number of com- 
pressor runs. During the entire day 108 runs were made, the 
average hourly nimiber being 4.5 runs. The short run included 
18 runs, the average duration of each being practically the 
same as in the preceding case, somewhat over five minutes. 
This is at the rate of 7.6 runs per hour. The strain upon the 
capacity of the compressor is further sho^Ti by the somewhat 
lower gage pressure in the storage tanks, indicating that at 
times it was necessary for cars to draw air before the maximum 
pressure had been reached. No great disadvantage could re- 
sult from this, however, as the storage tanks were of such large 
capacity that, in case of a congestion of cars at the compressor 
station, the air could be drawn off more rapidly than it was 
being compressed, without a serious lowering of the pressure. 

The automatic controller was adjusted to start the motor 
when a minimum pressure of 275 lbs. had been reached, and 
to stop it when the air pressure reached 300 lbs. The aver- 
age of all "starts" for the range of pressure allowed by the 
governor was slightly over 25 lbs., and, when the call on 
the compressor was not unduly severe, the pressure was main- 
tained substantially as desired. The average value is some- 
what below the average of maximimi and minimum values in 
Test No. 20 and above this average in Test No. 21. There is 
not necessarily any fixed relation between these pressures, as 
the maximum and minimum averages each cover a number of 
values equal to the nimiber of runs, and distributed at irregular 
intervals, while the average pressure is obtained for the entire 
test. 

The temperature of the stored air is about 40° Centigrade 
or 104° Fahrenheit, being substantially the same for the two 
tests. It might be expected that the temperature would be 
lower in the second than in the first test on account of the more 
rapid circulation of compressor cooling water. This is the case 



286 ELECTRIC RAILWAY TEST COMMISSION 

if similar periods in the two days are compared, but the average 
temperature is lowered in Test No. 20 by the cool period during 
the night and early morning. 

The data relating to the volume of air compressed show 
that the compressor delivered to the storage tanks 68.7 cu. 
ft. of free air per minute, compressed to a pressure of 280.8 
lbs. in Test No. 20. The corresponding valve for Test No. 
21 shows 76.9 cu. ft. per minute at 276.2 lbs. pressure. 
Of the total quantity of air compressed, 95 per cent reaches 
the cars, the remaining 5 per cent being lost in the leakage at 
valves and joints. 

In Test No. 20, 10,400 lbs. of water circulated around 
the cylinders and intercooler and absorbed the greater part of 
the heat produced by the compressor. That this circulation 
was sufficient to maintain the cylinders at a safe working tem- 
perature, is evident from a study of the tables showing the 
variations in temperature. A more rapid circulation of cooler 
water, however, should improve the conditions of operation, 
as with the resultant increase in density more air is compressed, 
without increasing the friction in the compressor. In Test 
No. 21, the water was more rapidly circulated and was lower in 
temperature than in Test No. 20, and hence an improvement 
in economy of operation would be expected. That this is the 
case is brought out in the latter part of the discussion. It will 
be noted that the amount of heat absorbed per pound of cool- 
ing water circulated, is 24.6 B.T.U. in Test No. 20 and 16.7 
B.T.U. in Test No. 21. This naturally follows from the more 
rapid circulation of the cooling water in the second test. 

The general data are smnmed up in the values showing the 
energy per pound of air compressed and per cubic feet of free 
air compressed. These data render possible the calculation of 
the cost of compressing the air for any particular case. 

The Electrical Data. — The electrical readings show that 
the motor provided for the purpose of driving the compressor 
was of ample capacity. It was rated at 50 horse power, while 
the average electrical input was but slightly over 30 horse power 



COMPRESSOR STATION TESTS 287 

in each test. In Table XXXII are given, for each test, both the 
average power for the individual runs and the average power 
for the entire test. 

As there were forty compressors situated in different stations 
located in various sections of the city, it is evident that the 
power drawn from the central station to supply these air com- 
pressors did not fluctuate over very wide limits, since the com- 
pressors at the various stations would be starting and stopping 
at irregular intervals, and the fluctuations in load at the several 
stations would be practically neutralized as far as the load on 
the central station is concerned. 

From Table XXXII it will be seen that the number of cars 
in operation during the twenty-four-hour test was twenty-two, 
as against an average of forty-two cars in operation during the 
2.35-hour test. The increase in the average mmiber of cars 
in operation during the latter test is due to the fact that it 
covered a very busy period in the day. From the results of 
the service test shown in Chapter III, it is found that the aver- 
age power taken by a single car during a twelve-hour run was 
approximately 25.3 kilowatts. Data as to the average power 
taken by such a car over a twenty-four-hour period are not 
available, but it is probable that the average power would not 
differ greatly from this amount. Considering the average 
power taken by a car as 25.3 kilowatts in each test, it is found 
that the average total power taken by cars during the twenty- 
four-hoiu" test is 556.6 kilowatts, while that taken during the 
2.35-hour test is 1062.6 kilowatts. The average power taken by 
the compressor station is shown to be 9.23 kilowatts during the 
twenty-four-hour test as against 15.0 kilowatts in the 2.35-hour 
test. From these data may be calculated the relation between 
the power taken by the compressor plant, in comparison with 
that taken by the cars which are supplied with compressed air 
from this plant. The data show that in the twenty-four-hour 
test the power taken by the compressor plant is 1.7 per cent of 
that taken by the cars supplied with air from this plant, while 
in the 2.35-hour test this value is 1.4 per cent. 



288 ELECTRIC RAILWAY TEST COMMISSION 

Temperature Data. — For the purpose of studying the 
variations of the several temperatures (both of the air and of the 
coohng water) during the different periods of the day, the 
twenty-four-hour run was divided up into eight three-hour 
periods, all of the temperatures being averaged for each period. 
In order to appreciate these data, it will be necessary to remember 
that the heavy loads occurred between 4.00 p.m. and 8.00 p.m., 
and between 5.00 a.m. and 9.00 a.m., with a smaller congestion 
of load at about the noon hour. The variation in temperature 
of the room was not very great, being about 10° C. or 18° F. 
between midnight and noon. At the point where the air entered 
the compressor, the variation was even less than this amount, 
being less than 40° C. during the entire test. It may be assumed 
for comparison, that the air is received at a constant tempera- 
ture by the compressor. The temperature in the intercooler, 
Avhere the air passes after the first stage of compression, shows 
a fluctuation following very closely the congestion of load upon 
the station, but lagging slightly in time behind the periods of 
heaviest load. This is true also, and to a much greater extent, 
in the case of the temperature at the discharge pipe of the com- 
pressor, at which point the air reaches its maximum tempera- 
ture. Between the hours of 5.00 p.m. and 8.00 p.m., this tem- 
perature rose to a value of 119.7° C. or 247° F. After this 
period, the temperature decreased until the period in which 
none but " owl" cars were running, that is, from 2.00 a.m. 
to 5.00 A.M., when a minimum value of 56.50 is reached. 
The temperature then rises, reaching another high value be- 
tween 8.00 A.M. and 11.00 a.m., when the load is again very 
heavy. 

The temperature in the storage tanks does not show much 
variation. This is to be expected, as the tanks are large and 
exposing a considerable surface for radiation. The air enters 
the tanks slowly as compared with the total volume contained 
by them, and ample time is afforded for radiation. In addition, 
as these storage tanks are located high in the room where the 
air temperature has a high value, they are in a region where the 



COMPRESSOR STATION TESTS 289 

surrounding temperature is not greatly above the temperature 
within the storage tanks. 

A study of the temperatm-es of the cooling water, arranged 
in three-hour periods, brings out substantially the same char- 
acter of fluctuation as that shown by the air, excepting that the 
range of such variations is smaller, on account of the greater 
specific heat of the water. The greatest variation of the tem- 
perature of the circulated water, at different parts of the sys- 
tem, occurs between that entering the high-pressure cylinder 
jacket and that leaving the intercooler. This rise in tempera- 
ture is a measure of the amount of heat absorbed by each 
poimd of water passing through the jackets. The average 
difference of temperature at these two points, for the entire 
test, is 13.75° C. This difference does not follow the same law 
as that of the variation of the temperature in different parts 
of the day, owing to the fact that, when the load upon the 
station is heaviest, the circulation of water is most rapid. 

The General Summary. — In Table XXXV a general sum- 
mary is given of the data for the test, arranged in three-hour 
periods. The volumes of air compressed during the different 
periods are accurately indicative of the load upon the station. 
It will be noted that the proportionate leakage is much greater 
when the load is light, showing that this leakage does not vary 
greatly with fluctuations in load. It is not possible to accu- 
rately estimate the leakage by three-hour periods, as, during 
several of these periods, more air was taken out than was de- 
livered by the compressor. The circulation of cooling water is 
also in proportion to the load upon the station. This follows 
from the automatic action of the "air-lift," which was em- 
ployed to raise the water to the storage tanks; the air for this 
purpose being derived from the intercooler, or receiver, between 
the high and low-pressure cylinders. 

Some of the thermodynamic results of the tests are indicated 
by the data showing the manner in which the heat was ab- 
sorbed by the cooling water in different parts of the compres- 
sor. The amounts absorbed in the three jackets are sub- 



290 ELECTRIC RAILWAY TEST COMMISSION 

stantially the same, being greatest in the low-pressure cyhnder, 
and least in the high-pressure cylinder. The total heat 
absorbed, considered by three-hour periods, shows a close 
relation to the load upon the station; varying from 18,400 
B.T.U. per hour to 3090 B.T.U. per hour, between the time of 
heaviest and of hghtest load. 

The electrical energy absorbed during the different periods 
is nearly proportional to the quantity of air compressed in 
each case. This is due to the fact that the motor worked at 
a high efficiency while actually in operation, being automati- 
cally shut down when the pressure reached its upper limit. This 
relation is further indicated by the manner in which the run- 
ning time of the motor, in each period, follows the quantity 
of air compressed during that period. As a matter of fact, 
the motor received somewhat less power from the line when 
the load was heaviest, on account of the lower pressure on the 
trolley circuit. 

It is seen that the storage reservoir pressure was maintained 
at a high average value, except at the periods of heavy loads. 

The data resulting from Test No. 20, having been condensed 
into a few items in Table XXXVII, give a detailed compari- 
son of the relative temperatures for Tests Nos. 20 and 21, cov- 
ering two similar periods on successive days, but with different 
methods of cooling the compressor cylinders. The room tem- 
perature, and consequently the temperature at the compressor 
intake, was 2.8° C. lower in Test No. 21 than in Test No. 20, 
so that the differences in air temperatures in the two tests nmst 
be reduced by this amount for an accurate comparison. After 
making this correction, the data show that the intercooler 
temperature has been lowered by 8.9° C. (16.0° F.), while for 
the discharge pipe, the hottest point in the air circuit, the re- 
duction has been 9.5° C. (17.1° F.). 

The reduction in the water temperatures is even greater 
than that in the air temperatures. The water was received 
from the city mains at 22.7° C. (73° F.), which was 14.4° C. 
(25.9° F.) lower than that delivered from the storage tanks. 



COMPRESSOR STATION TESTS 291 

It enters the low-pressure cylinder 16.0° C. (28.8° F.") cooler; 
it enters the intercooler 24.0° C. (43.2° F.) cooler; and it leaves 
the intercooler 19.2° C. (35.6° F.) cooler in Test No. 21 than 
in Test No. 20. This indicates a considerably better per- 
formance of the compressor in Test No. 21 than in Test No. 20. 

In Table XXXVIII is given a comparative summary of the 
general data for two similar periods, corresponding to those in 
Table XXXVII. The second test showed a somewhat heavier 
duty upon the station than did the first, the difference being 
about 21 per cent. The weight of the water circulated was 
nearly two and one-half times as great. This increased circu- 
lation of water at a lower temperature resulted in the absorp- 
tion of over 50 per cent more heat in the second test than in 
the first. 

The general comparative results of the tests are shown in 
Table XXXIX, in which all of the quantities have been re- 
duced to rates by means of which an exact compression can be 
made. The saving due to the use of the city water is 4.7 watt- 
hours per pound of air compressed. The saving which would 
result in one day of 24 hours, is sho\Am by applying this rate to 
Test No. 20. In this test 3201 lbs. of air were compressed, 
and a saving of over 15 kilowatt-hours would have resulted 
from the use of the city water. Whether or not this energy 
would offset the cost of the water can be determined for any 
particular case. The saving would be greater in summer than 
in winter, as the radiation of heat from all parts of the plant 
is more rapid in the latter period of the year. 



*.,. 



CHAPTER VIII. 

BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 
EQUIPPED WITH AIR BRAKES. 



Objects of the Tests. 

The primary object of these tests was to determine the 
amount of air necessary to make an average stop under normal 
conditions in city service and to ascertain the amount of elec- 
trical energy recmired to compress air for making such a stop. 
Further, it was desired to compare the amount of electrical 
energy used for braking by the storage system, and by that 
employing a car motor compressor. Finally, the plan com- 
prised a series of tests to determine the comparative perfor- 
mance of a car motor compressor when operating upon a car 
under ordinary service conditions, and again when operating 
under stand test conditions. 

SYNOPsrs OF Results. 

The following tables give in condensed form the general 
results of the tests. Table XL shows the general results of 
service braking tests Nos. 26, 27, and 28. Table XLI gives 
similar data for the stand tests. Detailed tables are shown in 
the several parts of the chapter. 

Section A. Tests upon the Cars. 

GENERAL CONDITIONS OF THE TESTS. 

The storage-air tests comprised air measurements of the 

entire number of cars on the Park Avenue and Compton Avenue 

lines of the St. Louis Transit Company, which were normally 

operated by the storage system. In connection with the tests 

292 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 293 
Synopsis of Results. 

Table XL. — Synopsis of Results. Braking Tests of Double-Truck City 

Cars. 

August and September, 1904. 



Duration of test, hours 

Actual running time, hours 

Number of compressor runs 

Number of cars tested 

Total mUes run 

Total car hours 

Total ton miles 

Total volume of free air received at brake 
reservoir, cu, ft. 

Average gage pressure in high-pressure 
reservoir, lbs. 

Average gage pressure in low-pressure 
reservoir, lbs. 

Total number of stops 

Total number of brake appUcations 

Average brake cylinder pressure, lbs 

Total electrical energy used in compressing 
air, kilowatt-hours. 

Electrical energy used per cu. ft. of free 
air compressed, watt-hours. 

Electrical energy used per stop, watt-hours 

Electrical energy used per brake applica- 
tion, watt-hours. 

Electrical energy used for braking per car- 
hour, watt-hours. 

Electrical energy used for braking per car- 
mile, watt-hours. 

Electrical energy used for braking per ton- 
mile, watt-hours. 

Volume free air used per stop, cu. ft 

Volume free air used per brake application, 
cu. ft. 

Volume free air used per car-hour, cu. ft. 

Volume free air used per car-mile, cu. ft. . 

Volume free air used per ton-mile, cu. ft. . 

Ratio of electrical energy used in brakes 
to energy used by car motors, per cent. 

Weight of air delivered by compressor per 
horse-power minute, lbs. 

Power to compress to above pressure one 
cu. ft. free air per minute, E. H. P. 



Test 
No. 
22 



24.00 

9.80 

108 

51 

4,608 

477.0 

96,900 

38,515 

195.0 

46.2 



221.9 
5.49 



465 
48.1 
2.25 



80.7 

8.35 

.39 

1.70 

.155 

.463 



Test 

No. 

23 



11.75 



1 

97.0 

11.75 

2,180 

819 

164.6 

43.7 

572 
1,137 
22.2 
4.71 

5.49 

8.25 
4.15 

400 

48.6 

2.16 

1.43 

.68 

69.5 
8.44 
.375 
1.75 

.155 

.463 



Test 
No. 
24 



12.6 

1.91 

419 

1 

117.8 

12.6 

2,650 

812 



49.3 

483 

1,730 

16.0 

3.26 

4.02 

6.74 
1.9 

259 

27.7 

1.27 

1.68 
.47 

64.4 
6.90 
.310 
1.01 

.223 

.322 



Test 

No. 

25 



11.75 

1.63 

351 

1 

111.9 

12.75 

2,520 

761 



47.0 

503 
1,276 
21.6 
2.95 

3.96 

5.86 
2.3 

231 

26.4 

1.17 

1.51 
.60 

58.7 

6.80 

.300 

.98 

.232 

.312 



Test No. 22. — Storage system, 51 cars, 24 hours. 
Test No, 23. — Storage system, 1 car, 11 .75 hours. 
Test No. 24. — Motor-compressor system, wet track. 
Test No. 25, — Motor-compressor system, dry track. 



294 



ELECTRIC RAILWAY TEST COMMISSION 



Table XLI. — Synopsis of Results. Stand Tests of Motor Compressor, 

November, 1904. 



Duration of test, hours 

Actual running time, hours 

Total number of runs 

Average temperature of air in room, degrees C . . 

Average current, amperes 

Average pressure, volts 

Average power, watts . . 

Average power, E. H. P 

Total energy supplied, watt-hours 

Average temperature in reservoir 

Speed of compressor axle, R. P. M 

Average gage pressure before runs, lbs. per sq. in. 
Average gage pressure after runs, lbs. per sq. in. . 

Average rise in gage pressure, lbs. per sq. in 

Average pressure pumped against, lbs. per sq. in. 
Total volume free air compressed at 0°C. and 14.4 

lbs. barometer, cu. ft. 
Energy per cu. ft. free air compressed, watt-hours 
Weight of air delivered by compressor per H. P. 

minute, lbs. 
Power to compress to above pressure, one cu. ft. 
free air per minute, E. H. P. 



Test 


Test 


No. 


No. 


26 


27 


6.95 


4.95 


1.93 


.44 


116 


141 


13.40 


13.40 


3.42 


3.12 


537.2 


546.1 


1,840 


1,705 


2.47 


2.29 


3,552 


754 


17.40 


15.10 


219 


242 


44.70 


43.52 


72.00 


50.78 


27.30 


7.26 


93.00 


47.15 


970 


328 


3.66 


2.30 


.243 


383 


.295 


.185 



Test 
No. 

28 



7.11 

.68 

95 

17.60 

3.19 

548.0 

1,750 

2.34 

1,187 

19.90 

250 

43.48 

60.59 

17.11 

52.03 

488 

2.43 
.363 

.195 



Test No. 26. — Against constant pressure, 93 lbs. 
Test No. 27. — Against pressure from 43.5 to 50.8 lbs. 
Test No. 28. — Against pressure from 43.5 to 60.6 lbs. 



upon the entire system special tests of individual cars were 
made, these cars all being equipped with the storage-air appa- 
ratus; and in addition tests were made on Car No. 2600 equipped 
with a motor compressor, in addition to the same kind of brake 
cylinders and rigging used in all the tests. 

The line selected for the car braking tests was the same as 
that supplied with air from the compressor station, the tests 
of which were described in Chapter VII. Upon this line were 
operated double-truck cars of two types. One of these was 
like Car No. 2600, upon which service tests were also made as 
is fully described in Chapter III. At the times of congested 
traffic, additional cars of an older and lighter style were placed 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 295 

upon the line. These cars, however, had approximately the 
same passenger capacity and maintained the same schedule as 
the heavier ones. The aA^erage number of cars upon the line 
during an entire day was 22, and the average number during 
the time of heaviest traffic was 42. Each car required an 
average power input of 25.3 kilowatts. The total number 
operated upon a single day was 51. The newer type of cars 
weighed 20 tons, fully equipped, while the older cars averaged 
approximately 16 tons. 

Braking Equipment of the Cars. 

Cars Equipped for the Storage System. — All cars oper- 
ated by the St. Louis Transit Company were equipped with 
storage reservoirs, designed to carry sufficient air at 300 lbs. 
pressure to operate the brakes for thirty or more miles of car 
travel. The arrangement of tank and brake cylinder with 
piping and brake rigging is sho^Mi in Fig. 78. The storage 
reservoirs, two in number, were located under, and at about 
the center of the car, one being on each side. The reservoirs 
were 18 in. in diameter and 6 ft. long, and each had a capacity 
of about 9.62 cu. ft., giving at 300 lbs. pressure a total capacity 
equivalent to 420 cu. ft. of free air at 14.4 lbs. absolute pres- 
sm'e. The storage reservoirs were charged from the compres- 
sing station, and the pipe leading from the coupling to the 
reservoirs contained an ordinary valve and a check valve to 
prevent loss of air. From the storage tanks air was supplied, 
through a reducing valve, to a service reservoir 14 in. in diam- 
eter and 33 in. long, which contained approximately 4400 cu. in. 
The reducing valve was arranged to maintain a pressure of 45 
lbs. on the service reservoir side, regardless of the pressure on 
the other side. 

From the service tank, the air was conducted to the engineer's 
valve at the front of the car, and from there it passed to 
the air brake cylinder, which was 10 in. in diameter, with a 
12 in. stroke. The brake rigging was similar to that used in 
other systems of braking, a hand brake being supplied for 



296 ELECTRIC RAILWAY TEST COMMISSION 

emergency use. The engineer's valve was of the standard 
O.V. J. type of the Westinghouse Traction Brake Company. 
This was a three-way valve, in one position connecting the 
service tank to the brake cylinder, and in the other position 
connecting the air brake cylinder to the exhaust. In an inter- 
mediate position the air supply was cut off without opening 
the exhaust, and the cylinder pressure was maintained at its 
previous value except as reduced by leakage. Each car was 
equipped with a gage connected to the high pressure reservoir, 
and located in the front vestibule. 

Car No. 2600 was selected for the special tests upon an indi- 
vidual car. The power end control equipment of this car is 
fully described in Chapter II. 

Car Equipped with Motor-Compressor. — Car No. 2600 
was employed for the motor-compressor tests, the brake cylinder 
and rigging being identical with those previously used. 

The compressor equipment, manufactured by the National 
Electric Company, was installed beneath the floor of the car 
on a frame suspended from the sills, and delivered air at from 
45 to 60 lbs. pressure into a storage tank through a flexible hose 
section and such piping as would allow the tanks and com- 
pressor to be placed in the best relative position. The com- 
pressor was of the type known as AA-1, consisting of a 500- volt, 
4-pole, series woimd motor connected through a spiral tooth 
reduction gear to a pair of 5 X 2J-iii. cylinders, mounted side 
by side in a horizontal position, with cranks 180° apart. The 
motor was rated at 2.2 horse-power, which amount of power 
was expected to deliver 11 cu. ft. of air per minute when 
pumping against 90 lbs. pressure, and with the compressor 
making 195 revolutions per minute. The motor was started 
and stopped automatically at the lower and upper limits of 
pressure respectively, by a governor operated by a solenoid 
plunger which opened and closed a contact in the main com- 1 1| 
pressor circuit. The motor was entirely enclosed, and its base « 
formed the top cover for the compressor, the outside dimen- 
sions being 211| in. long, 18^^ in. wide, and 16f in. deep. 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 297 
Description and Results of the Tests 

TEST NO. 22. average CONSUMPTION OF AIR BY CARS 
EQUIPPED WITH STORAGE TANKS. 

The general method followed in determining the average 
amount of air used by the different cars on the line consisted 
in taking readings of the car gages, each time a car took air at 
the compressor station. This operation was continued during 
the entire period of the station tests, as described in Chapter 
VII. 

A special test was made in more detail to determine the 
amoimt of air used on each trip by a few selected cars, and to 
ascertain the number of miles which could be run with one 
charge of air. 

The number of cubic feet of free air used by each car, was 
determined from the reduction in the gage pressure in a manner 
similar to that employed in the compressor station tests. In 
order to secure accuracy in this measurement, it was neces- 
sary to compare every car gage on the line with a standard 
gage, suitable corrections being made in the readings. 

Incidentally, an opportunity was afforded to study the char- 
acteristics of individual motormen in the matter of handling 
the air brakes, as it is generally understood that by careful 
handling a motorman can produce a considerable saving in air 
consumption. 

Measurements Made. 

Observers were stationed at the hose-box from which the 
cars took air, and they recorded the following data as each car 
took a charge. 

Time of charge. 

Number of car taking charge. 

Air temperature at hose-box, before, during, and after each 
charge. 

Pressure at hose-box at end of each charge. 

Pressure on car storage reservoir gage, before and after each 
charge and its maximum value. 



298 



ELECTRIC RAILWAY TEST COMMISSION 



Pressure on service reservoir before and after each charge. 

Numbers of cars passing without charging. 

No special preparation was necessary for this test, as the 
apparatus was installed in connection with the compressor 
station test. 

WORKING UP THE RESULTS. 

The readings were first corrected in accordance with the cali- 
brations, and they were then entered on a "combined log sheet," 
as in the preceding tests. The measurements made upon each 
car were arranged together so that the air record of the car 
would show the total amount of air taken during the day, and 
at what times air was taken. No attempt has been made to 
put these data into graphical form, but the general results are 
shown in Table XLII, and in the synopsis given at the begin- 
ning of the chapter. In addition to the data obtained from 
the test, the trip sheet records kept by the St. Louis Transit 
Company, were employed in the determination of the total 
number of round trips made during the test. 

RESULTS OF THE TESTS. 

The following tables show in condensed form the results ob- 
tained from Test No. 22. 



Table XLII, — Test No. 22. General Summary of Results. 



Total number of cars in operation 

Total number of car-miles run during test ^ 

Total number of car charges 

Average number of car charges, per hour 

Maximum number of car charges, per hour 

Maximum distance run per charge, miles 

Total volume of air supplied by station, cu. ft 

Average volume of free air taken, per charge, cu. ft 

Average temperature of air at start, degrees C 

Average temperature of air during charge, degrees C 

Average temperature of air at end of charge, degrees C 

Average temperature of atmosphere, degrees C 

Average gage pressure in hose-box, at end of charge, lbs. per 

sq. in 

Average car storage reservoir pressure, before charging, lbs. per 

sq. in 



51 

4,608 

211 

8.8 

17.0 

21.8 

38,515 

183 

25.1 

25.1 

25.1 

24.4 

267 

122.5 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 299 
Table XLII. — Continued. 



Average maximum car storage reservoir pressure, lbs. per sq. in. 

Average final car storage reservoir pressure, lbs. per sq. in 

Average rise in pressure during charge, lbs. per sq. in 

Average car service reservoir pressure before charging, lbs. per 

sq. in 

Average car service reservoir pressure, after charging, lbs. per 

sq. in 

Average number of round trips (10.53 miles) per charge 



276 

269 

146.5 

44.8 

47.7 
2.08 



From the above data and the results of the compressor 
station tests, in which it was found that the electrical energy 
used per 1000 cu. ft. of air delivered was 5.75 kilowatt-hours, 
a number of deductions were made as follows: 



Table XLIII. — Results of Test No. 22. Compression Data. 



Electrical energy to deliver 1,000 cu. ft. of free aii:, k. w. hours 

Total car-miles for test 

Total car-hours for test 

Total ton-miles for test ^ 

Total A'olume of free air received, cu. ft 

Volume of free air used per car-mile, cu. ft 

Volume of free air used per car-hour 

Volume of free air used per ton-mile 

Electrical energy used for compressing air per car-mile, watt- 
hours 

Electrical energy used for compressing air per car-hour, watt- 
hours 

Electrical energy used for compressing air per ton-mile, watt- 
hours 



5.75 

4,608 

477 

98,400 

38,515 

8.35 

80.7 

.39 

48.1 

465 

2.25 



1 Fifteen of the cars weighed with average load, 18.5 tons each ; 36 of the cars weighed 
with average load, 22.5 tons each. 

As it was impossible to measure the number of stops made 
by all of the cars on the line during Test No. 22, it was necessary 
to estimate these from the results of Tests Nos. 23, 24, and 25, 
which covered a total of nearly 30 round trips, or over 325 
miles. These tests covered the time between daylight and 
dark, and the average number of stops per mile was 4.8. This 
may be reduced to 4.5 to cover the few cars which operate 
during the night, and upon this basis an additional number of 
items may be calculated. 



300 



ELECTRIC RAILWAY TEST COMMISSION 



Table XLIV. — Results of Test No. 22, Stop Data. 



Stops per mile (estimated) . 

Total miiles run 

Total stops (estimated) 

Volume of free air used per stop, cu. ft 

Electrical energy used for compressing air per stop, watt-hours 



4.5 

4,608 

20,736 

1.85 

10.7 



In order to show the rate at which the cars took air during 
the entire 24 hours, Table XLV has been prepared. 



Table XLV. — Air Taken by Cars. 



Time. 


No. OF Cars 
Charged. 


Total 

Volume 

OF Air Taken. 


Average 

Volume 

of Air Taken 

PER Car. 


2-3 p.M 

3-4 p.M 

4—5 p.M 


8 

12 

14 

12 

13 

11 

10 

7 

9 

13 

11 

15 

17 

14 

14 

8 

9 

7 

7 


Cu. Ft. 
5,750 

6,910 

5,120 
2,515 
7,210 

6,280 

4,730 


Cu. Ft. 
169 


5—6 p M 




6-7 p M 


192 


7-8 p.M 

8-9 p.M 




9-10 p.M 


197 


10-11 p.M 




11—5 A.M 


193 


5—6 A.M 




6-7 A.M 


168 


7-8 A.M 




8-9 A.M 




9-10 AM 


174 


10-11 AM 




11-12 A.M 




12-1 P.M 


203 


1-2 P.M 








Total 


211 


38,515 


Average 183 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 301 

TEST NO. 23. PERFORMANCE OF A CAR EQUIPPED WITH 
STORAGE-AIR SYSTEM OF BRAKING. 

For the purpose of studying in detail the performance of a 
typical city car equipped with a standard outfit as used at 
St. Louis, Car No. 2600 was provided with instruments for 
measuring all quantities affecting the braking. Special piping 
was installed in order to bring the instruments into convenient 
position for reading as shown in Fig. 84. 

The measurements arranged for were as follows: 

Storage reservoir pressure. 

Service reservoir pressure. 

Air brake cylinder pressure. 

Brake applications. 

Speed of car. 

Distance traversed. 

Number and duration of stops. 

These data were sufficient to permit of the calculation of the 
volume of air received from the compressing station, and the 
relation between the consumption of this air and the number 
of stops made. 

In determining the various pressures, Amierican indicating 
gages were employed, and these were read at five-second in- 
tervals throughout the tests. A Crosby recording gage was 
connected to the brake cylinder during a part of the tests, but 
it was found that a more reliable method of determining this 
pressure was to read it from an indicating gage each time a 
brake application was made, noting also the time of each appli- 
cation. Thus, one observer obtained data for determining the 
number of brake applications in a given time, the pressure of 
each of such applications, and the time at which each occurred. 
The recording gage was afterward connected to the service 
reservoir, in which the pressure did not vary greatly. The 
speed of the car was obtained by means of a Boyer railway 
speed recorder which was checked by noting the time of pass- 
ing certain points in the route, and thus the distance traveled 



302 



ELECTRIC RAILWAY TEST COMMISSION 



in a given time was also determined directly. An observer 
noted the time of making each stop and its duration, thus giv- 
ing data permitting of a comparison of the number of stops 
and the number of brake applications. 

WORKING UP THE RESULTS. 

The data were first arranged in tabular form after correction 
of the instrument readings by calibration, and from these values 




To Brake Lever 



To Brake. Cyl-Gase: ^ 



To Tank G/k&e. @J=^ 




^ 



oTo ReiEASING- 

Coii_ , 

@ ^To Engineers Vaive. 

Exhaust 
To Cnsineers Valvb 

Fig. 84. — Piping of Car 2600, Equipment vuitti Motof Compressor. 

the deductions were made. No attempt was made to put 
the data into graphical form. 

RESULTS OF THE TESTS. 

The general results of the tests have already been given in 
the synopsis in convenient form for comparison. The more 
detailed results are given in Table XL VI. 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 303 



Table XLVI. — Test A'o. 23. General Summary of Results. 



Weather conditions 

Weight of car with average load, tons 

Total duration of tests, hours 

Total number of round trips 

Total distance covered, miles 

Total number of stops 

Average number of stops per mile 

Total number of brake applications 

Average number of brake applications, per mile 

Average number of brake applications, per stop 

Average storage reservoir pressure, lbs. per sq. in 

Maximum storage reservoir pressure, lbs. per sq. in 

Minimum storage reservoir pressure, lbs. per sq. in 

Average service reservoir pressure, lbs. per sq. in 

Average brake cylinder pressure during brake applications, lbs. 

per sq. in. 

Schedule speed of car (including stops), M. P. H 

Maximum speed of car (approximate), M. P. H 

Number of times storage tank was charged from compressing 

station. 
Average storage reservoir gage pressure before charging, lbs. per 

sq. in. 
Total volume of free air received from compressing station, cu. ft. 

Average volume of free air received per charge, cu. ft 

Average distance of run per charge of air, miles 

Average number of stops made per charge of air 

Average number of brake applications per charge of air 

Average volume of free air used per stop, cu. ft 

Average volume of free air used per brake application 

Average volume of free air used per car mile, cu. ft 

Average volume of free air used per car hour, cu. ft 

Average volume of free air used per ton mile, cu. ft 

Electrical energy equivalent of air used, kilowatt-hours 

Electrical energy per stop, watt-hours 

Electrical energy per brake application, watt-hours 

Electrical energy per car mile, watt-hours 

Electrical energy per car hour, watt-hours 

Electrical energy per ton mile, watt-hours 

Ratio of electrical energy used in braking to that taken by 

motors, per cent 

Weight of air delivered by compressor to car per H. P. minute, 

lbs ^ 

Power to compress to above pressure 1 cu. ft. free air per minute, 

E. H. P 



clear 

22.5 

11.75 

9.2 

97.0 

572 

5.9 

1,220 

12.6 

2.14 

164.6 

265.0 

50.0 

43.7 

22.2 
9.12 

17.5 



248.2 

819 

164 

24. 2^ 

143 1 

284 

1.43 

.67 

8.44 

69.5 

.375 

4.71 

8.25 

4.15 

48.6 

400 

2.16 

1.75 

.155 

.463 



1 Calculated on the basis of four charges as car went to barn with fuU charge of air at 

end of test. 



304 



ELECTRIC RAILWAY TEST COMMISSION 



Table XLVII. — Air Consumption of Car 2600. Arranged by Round Trips. 
Storage Air System, Dry Track. Aug. 29, 1904. Test No. 23. 



Pk 


Time. 


Dis- 
tance 
Miles. 




OJ TO 

fa r o 


Cu. Ft. per 
Car Mile. 


Cu. Ft. per 
Brake Ap- 
plication. 


Cu. Ft. 

PER 

Car 
Hour. 


Tank Pressures. 


t; a p 




At Be- 
ginning 
of Run. 


At End 
of Run. 


w S s 




A.M. 




















1 


7:38- 8:50 


10.30 


121 


77.0 


7.48 


0.683 


64.1 


256 


192 


19.1 


2 


8:52-10:00 


9.64 


108 


70.3 


7.29 


0.651 


62.0 


190 


132 


23.4 


3 


10:05-11:00 


10.23 


95 


66.7 


6.51 


0.702 


61.7 


129 


74 


22.7 


4 


11:11-12:10 


10.63 


107 


105.5 


10.40 


0.984 


96.6 


251 


164 


24.7 


5 


P.M. 

12:16- 1:10 


8.89 


145 


105.0 


11.80 


0.723 


118.9 


164 


77 


29.5 


6 


1:20- 2:45 


10.22 


180 


131.3 


13.00 


0.736 


93.8 


231 


121 


24.3 


7 


2:50- 4:39 


10.53 


122 


84.9 


8.12 


0.702 


80.8 


117 


46 


23.6 


8 


4:42- 5:55 


10.63 


141 


79.1 


7.44 


0.569 


64.8 


262 


196 


21.1 


9 


5:55- 7:05 


10.63 


126 


67.5 


6.35 


0.536 


58.2 


196 


140 


21.0 



TESTS NOS. 24 AND 25. PERFORMANCE OF A CAR EQUIPPED 
WITH THE MOTOR-COMPRESSOR SYSTEM OF BRAKING. 

Car No. 2600 was supplied with a motor-compressor equip- 
ment as described earlier in the chapter, and instruments were 
obtained for making all measurements necessary to determine 
the efficiency of this system as compared with the storage 
system of braking. The particular purpose of the test was to 
study the operation of a motor-compressor equipment under 
actual working conditions. To this end the motor compressor 
was allowed to operate normally, and the quantity of air was 
determined by the rise in pressure in the tanks. It was realized 
that this plan is open to certain objections in that it is difficult 
to determine accurately, by means of pressure gages, the actual 
pressure existing, and this is particularly the case when it is a 
difference of pressure that is to be measured. Here the errors 
in reading the gages are multiplied in effect when two pressures 
differing only a few poimds are to be used for comparison. 
However, as this was the only practicable means of performing 
the desired test, a satisfactory degree of accuracy was obtained 
by extreme care in the reading of instruments and by careful 
calibration. The measurements made in connection with this 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 305 

test included: (1) service reservoir pressure before and after 
the operation of the compressor; (2) strokes of the compressor; 
(3) air brake cjdinder pressure; (4) brake applications; (5) speed 
of car; (6) distance traversed; (7) number and duration of 
stops. 

The arrangement of piping and of instruments for making 
the various measurements were as shown in Fig. 85. It will 

TO TI^OLLEY 
SWITCH 



'AGE. 



TO BfV^KE^CYL. 
TOSEf^lCETAN»^ 




GROUND 
Fig. 85. — Diagram of Connections, independent Motor, Compressor System. 



be noted in this figure that there was a connection from the 
brake cylinder piping to a special controller in the motor circuit. 
The function of this switch was to prevent air being used by 
the niotorman while it was being compressed. The pneumat- 
ically operated switch was closed whenever the brake was in 
operation. This arrangement was essential because the volume 
of air compressed by the motor-compressor was determined 



306 ELECTRIC RAILWAY TEST COMMISSION 

from the rise in pressure in the storage reservoir, hence any air 
drawn while the motor was in operation would not have been 
included in the measurements. 

ORIGINAL MEASUREMENTS. 

The original measurements may be divided into general 
classes as follows : (a) Those relating to electrical input ; (b) those 
relating to reservoir and brake cylinder pressures; (c) those 
relating to temperatures; (d) those relating to stops, distance, 
and speed; (e) those relating to brake applications; (/) those 
relating to motor-compressor speed. 

Electrical Measurements. 

The electrical measurements comprise those of current, 
e.m.f., and energy. The current was read on two instru- 
ments, starting current being noted on a higher-reading am- 
meter than the normal current. The maximum value of the 
starting current was read on the first-mentioned instrument, 
and immediately after obtaining this reading a switch which 
short-circuited the low-reading ammeter was opened, and there- 
after readings were taken of the steady current, the average 
value of this current being recorded. It was impossible to 
obtain the exact duration of the starting current, but this was 
afterward estimated from a large number of measurements 
covering the entire series of tests. The compressor volts were 
read every ten seconds. The energy for each run was deter- 
mined by means of a Thomson watt-hour meter, and readings 
were taken at the start and stop of each compressor run. 

Pressure Measurements. 

The brake cylinder pressure was read on an indicating gage 
connected by special piping directly to the head of the brake 
cylinder, while special piping was also connected to the storage 
reservoir. The brake cylinder pressure measurements were 
made whenever the brakes were applied, and the time of such 
application was also noted. In this test a Crosby recording 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 307 

gage was used on the brake cylinder as well as the indicating 
gage. The storage reservoir pressure was read at each start 
and stop of the motor compressor, the times of such starts and 
stops bemg also recorded. 

Temperature Measurements. 

The temperature of the air was noted at regular intervals 
throughout the day, and the average temperature of the atmos- 
phere for the test was thus obtained. An attempt was also 
made to determine the temperature of the air in the storage 
reservoir by means of an electric thermometer. A fine iron 
wire was wrapped spirally aroimd a wooden rod one foot in 
length, and this was inserted in the end of a steel plug which 
was screwed into the head of the storage reservoir. The ter- 
minals were brought out through the center of the rod, and 
through the wire was sent a small battery current, not suffi- 
cient in amount to raise the temperature of the wire to an appre- 
ciable extent. By means of sensitive Weston instruments the 
resistance of this wire was determined by finding the fall in 
pressure in the wire with a given current. The electric ther- 
mometer gave fairly consistent results, but it was found that 
the temperature variation of the air in the storage reservoir 
was so slight that it was unnecessary to make temperature 
measurements for the purpose of correcting the calculations 
of volumes of air compressed. In fact, the corrections which 
would have to be made for variation m temperature were very 
small compared with the errors of observations which would 
be expected in reading the indicating gages, so that the use of 
the thermometer was discontinued after it had been thoroughly 
tested. The temperature of the air in the storage reservoir 
was assumed to be the same as that of the outside air, which 
assumption was substantially correct, from the fact that the 
air passed through a considerable length of piping between the 
compressor and the storage reservoir, this piping acting very 
effectively as a radiator. 



308 ELECTRIC RAILWAY TEST COMMISSION 

The Distance and Speed Data, 

The time and duration of each stop and its location were 
carefully recorded. These data also furnished a means for 
determining the average speed between stops, thus checking 
the record on the Boyer instrument, which was used for produ- 
cing the distance-speed curve. In addition to the Boyer in- 
strument, there was operated a small generator driven by the 
car axle, which gave a record of speed on a time base. The 
indicating gage of the Boyer recorder was read from time to 
time, and the readings were recorded upon the paper tape of 
the instrument, thus checking the two measurements of speed 
made by this instrument. As an additional check upon the 
distance and speed measurements, the times of passing all street 
intersections were also recorded. 

Brake Application Data. 

From the indications of the brake cylinder pressure gage, 
the number and times of the brake applications were deter- 
mined, in connection with the pressure measurements already 
referred to. 

Motor-Compressor Speed Data. 

The number of strokes which the motor-compressor made 
during each compressor run was recorded on an engine counter. 
This was a Shaefer and Budenberg six-figure, counter-elect- 
rically operated by means of an electro-magnet. A contact 
device, attached to the pump, was closed once during each 
revolution. This contact device was connected in series with 
a battery and the electro-magnet of the counter. The revolu- 
tion counter was read before and after each run. As ihe motor 
was spirally geared to the compressor, the average speed of 
the motor during the run was calculated directly from the time 
of the compressor run and the number of strokes made by the 
compressor pistons. 

WORKING UP THE RESULTS. 

After the various data had been corrected by calibration, 
they were assembled on a "Combined Log Sheet" for reference 






14. 



la 



j^ 



30. 



i 



3 



Z 



3 IS 



30 



:>5 



20 



w- 



o 



BL 



15 



10 



44 



V 



SiQ 



4()0 



300 



2()Q 



100 



KK) 



75 



15 



10 



O 



150 



ilB 



O 



M 



O 



X2 
5 



1(X) 



iSQ 



"Bf 



■M^ 



0) 



3 



i 



n 



^bjy- 



±i_: 



Feet O 



I 



1 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 309 



in working up the final results. Fig. 86 shows a portion of 
the headings placed upon the "Combined Log Sheet." The 
explanation, which has already been made, will render unne- 
cessary a further discussion of this part of the work. 



No. 


Time, 


Power. 


Air Data. 








Gage Pressures. 


Tem. 


Volume. 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


13 


14 


15 


16 


<4-l 

o 

6 
12; 


c 
o 

be 

C 

1 

m 


d 

CM 
O 

< 


O 03 

Q 


11 

d 
6 

> 


W 
II 

I 

U 
> 


|ll 


Sx 

Or,-, 

"^11 


>> • 

ll 


.S 

'>> 
o 

m 

l-H 


1 

a 

'Stri 
03 C 

a 
1— ( 


o 

-a 

C 
c! 


(-1 

3 

0} 
O! 

V 

u 
o 

G 
1— 1 


83 

o 
.S 


1 
S 

1^ 

o o 

*- m 

.22 

o a 





No. of Instrument. 



Fig. 86. — Log Sheet Headings, Tests Nos. 24 and 25. 

It was found impracticable to put all of the data resulting 
from Tests Nos. 24 and 25 into graphical form, but the mate- 
rial has been put into tables, and such deductions have been 
made as will be found most useful. For the purpose of illus- 
tration and to indicate the manner in which the variables are 
related, the results of a single trip have been put into graphical 
form in Fig. 87. The results of this part of the test have been 
arranged upon a distance base. In this connection it is inter- 
esting to note that the same run has been illustrated on a time 
base in the service tests on tins car, which will be found in 
Chapter II, Part II. 

Electrical Measurements. 

In working up the electrical readings for the purpose of 
determining the total amount of electrical energy used per 
compressor run, the two sources of information were both used. 




Feet 



310 ELECTRIC RAILWAY TEST COMMISSION 

From the average current and volts and time, the total energy 
was determined, and the readings of the watt-hour meter were 
compared with the amount of energy thus derived. In obtain- 
ing the average current, some difficulty was experienced in de- 
ciding upon the duration of the sudden impulse in the current 
at the start. While almost instantaneous, this starting im- 
pulse was between two and three times the normal value of 
the current. A reasonable assumption for the duration of the 
starting current was made, and a satisfactory determination of 
the total energy was obtained by comparing the data calculated 
from the readings of pressure, current, and time with the read- 
ings of energy as shown by the watt-hour meter. 

Air Volume Measurements. 

The volume of air delivered to the storage reservoir by the 
compressor during each run was determined from the differ- 
ence in pressure before and after the run, from the average 
temperature during the run, and from the time interval of the 
run. From these data the volume of air compressed in terms 
of barometric pressure and at a temperature of zero degrees 
Centigrade was calculated by the plan employed in the station 
tests and described in Chapter VII. 

Speed and Distance Data. 

The speed data were taken from the Boyer speed recorder 
after calibration, which calibration was performed by jacking 
up the car and driving the car axle at various speeds. The 
speed of the car axle was determined by means of a watch 
and revolution counter. The record of the Boyer speed re- 
corder was checked by means of the time measurements made 
between known points on the line. In fact, the time and 
distance between each two successive stops were used to deter- 
mine the average speed of each car run. The Boyer records 
were integrated, and the average value of the speed was made 
to correspond with the actual value obtained above. The 
record produced by the generator geared to the axle was not 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 311 

entirely satisfactory, owing to the fact that a rubber-faced 
metal wheel was used to transmit the motion from the car 
axle to the generator. It was found that the contact between 
the rubber wheel and the car axle was not continuous, so 
that the jars due to passing over irregularities in the track 
rendered the readings imsatisfactory. 

Results of the Tests. 

The results of the tests have already been arranged in con- 
venient form for comparison with those of the other tests in 
the sjmopsis at the beginning of the chapter. It will be found 
convenient to refer to a somewhat more elaborate table show- 
ing the results of two similar tests, both with the motor-com- 
pressor, and these data are given in Table XL VIII, As far as 
possible the two tests were kept exactly alike except in regard 
to the condition of the track, the first test being made on a 
wet track, the other being on a dry track. While the primary 
purpose of the test was to obtain the comparative energy 
consumption of the motor-compressor and storage systems, 
advantage was taken of the opportunity to compare the per- 
formance of the same car on different days with the same 
equipment. The advantage of this duplication of the work 
was not only to show the difference due to the condition of the 
track, but it doubled the number of readings taken, and thus 
increased the value of the results of the test by increasing the 
accuracy of the deductions. 



312 ELECTRIC RAILWAY TEST COMMISSION 

Table XL VIII. — Tests Nos. 24 and 25. General Summary of Results. 



Condition of track 

Total duration of test, hours 

Total number of round trips (10.53 mUes) 

Total distance covered, mUes 

Total number of compressor runs 

Total running time of compressor, hours 

Average line pressure, volts 

Average compressor current, amperes 

Average maximum value of compressor current, am- 
peres. 

Average compressor power (running time), watts . . . . . 

Total electrical energy used, k.w. hours 

Average electrical energy per run, watt-hours 

Average reservoir pressure before compressor run, lbs. 
per sq. in. 

Average reservoir pressure after compressor run, lbs. 
per sq. in. 

Average rise in pressure during compressor run, lbs. 
per sq. in. 

Average air temperature during test, degrees C 

Average number of compressor revolutions per run . . . . 

Total volume of air compressed, cu. ft 

Average volume of air compressed per run, cu. ft 

Electrical energy per cu. ft. of free air compressed, 
watt-hours. 

Average cu. ft. of free air compressed per kilowatt-hour 

Total number of stops 

Average number of stops per mile 

Total number of brake applications 

Total number of brake applications per mile 

Average brake cylinder pressure during brake applica- 
tions. 

Schedule speed of car, mile per hour 

Average maximum speed of car, mUes per hour (ap- 
proximate). 

Average volume of free air used per stop, cu. ft 

Average volume of free air used per brake application . 

Average volume of free air used per car-mUe 

Average volume of free air used per car-hour 

Average volume of free air used per ton-mUe 

Electrical energy used for braking per stop, watt-hours 

Electrical energy per brake application, watt-hours . . . . 

Electrical energy used for braking per car-mile, watt- 
hours. 

Electrical energy per car-hour, watt-hours 

Electrical energy per ton-mile, watt-hours 

Ratio of energy used for braking to that used in motors, 
per cent. 

Weight of air delivered by compressor per H. P. minute 

Average pressure pumped against lbs. per sq. in 

Power to compress to above pressure, 1 cu. ft. free air 
per minute, E. H. P. 



Test 24. 



wet 

12.6 

11.15 

117.8 

419 

1.91 

488.4 

3.5 

8.4 
1,710 
3.26 

7.8 
46.2 

52.5 

6.3 

24.0 
57.5 
812 
1.94 
4.02 

248 

483 

4.1 

1,730 

14.45 

16.0 

9.5 
16 

1.68 
.47 
6.9 

64.4 
.31 

6.74 
1.9 

27.7 

259 
1.27 
1.01 

.223 
49.3 
.322 



Test 25. 



dry 

12.75 

10.60 

111.9 

351 

1.63 

471.8 

3.84 

8.4 
1,810 
2.95 

8.4 
43.5 

50.5 

7.0 

22.4 
69.0 
761 
2.17 
3.96 

259 

503 

4.5 

1,276 

11.40 

21.6 

9.3 
16 

1.51 
.60 
6.8 

59.7 
.30 

5.86 
2.3 

26.4 

231 
1.17 

.98 

.232 
47.0 
.312 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 313 

Table XLIX. — Air Consumption of Car 2600. Arranged by Round Trips. 

Motor Compressor System. Wet Track. August 18, 1904. 

Test No. 24. 











Cu. Ft. 

Air 0° C. 

15 Lbs. 

Total. 




Cu. Ft. 


Cu. Ft. 






Dis- 


Brake 


Cu. Ft. 


PER 


PER 


Trip. 


Time. 


tance. 


Appli- 


PER Car- 


Brake 


Car- 






Miles. 


cations. 


Mile. 


Appli- 


Hour. 














cation. 






A.M. 














1 


7:06- 8:13 


10.63 


149 


56.9 


5.35 


.383 


56.9 


2 


8:14- 9:24 


10.63 


133 


71.6 


6.73 


.538 


65.2 


3 


9:26-10:36 


10.63 


132 


71.2 


6.72 


.542 


65.0 


4 


10:36-11:45 


10.63 


228 


75.5 


7.09 


.346 


65.7 


5 


11:45-12:52 

P.M. 


10.63 


160 


86.2 


8.10 


.332 


77.2 


6 


12:52- 1:58 


10.63 


185 


98.1 


9.21 


.530 


89.1 


7 


1:58- 3:03 


10.63 


149 


77.2 


7.24 


.518 


71.2 


8 


3:03- 4:04 


10.63 


130 


75.8 


7.02 


.583 


74.5 


9 


4:04- 5:19 


10.63 


133 


51.3 


5.17 


.414 


44.0 


10 


5:19- 6:33 


10.63 


139 


65.2 


6.13 


.470 


54.0 



Table L. — Air Consumption of Car 2600. Arranged by Round Trips. 

Motor Compressor System. Dry Track. August 24, 1904. 

Test No. 25. 











Cu. Ft. 

Air 0° C. 

15 Lbs. 

Total. 




Cu. Ft. 


Cu. Ft. 






Dis- 


Brake 


Cu. Ft. 


PER 


per 


Trip. 


Time. 


tance. 


Appli- 


PER Car- 


Brake 


Car- 






Miles. 


cations. 


Mile. 


Appli- 


Hour. 














cation. 






A.M. 














1 


6:30- 7:35 


9.40 


94 


49.0 


5.20 


.520 


44.5 


2 


7:35- 8:49 


10.63 


100 


72.4 


6.82 


.724 


68.2 


3 


8:49- 9:59 


10.63 


108 


84.8 


7.96 


.785 


73.4 


4 


10:03-11:05 


10.63 


96 


67.8 


6.29 


.697 


64.8 


5 


11:09-12:20 

P.M. 


10.63 


132 


79.2 


7.47 


.600 


68.2 


6 


12:21- 1:18 


10.63 


124 


66.5 


6.24 


.536 


69.9 


7 


2:33- 3:31 


9.40 


146 


58.6 


6.23 


.402 


61.0 


8 


3:35- 4:39 


10.63 


152 


68.8 


6.48 


.452 


65.2 


9 


4:43- 5:55 


10.63 


126 


67.7 


6.35 


.538 


56.3 


10 


5:55- 7:11 


10.63 


105 


65.7 


6.17 


.636 


52.0 



314 ELECTRIC RAILWAY TEST COMMISSION 

Section B. Stand Tests of a Motor Compressor. 
Tests Nos. 26, 27, and 28. 

OBJECTS OF THE TESTS. 

The primary object of this series of tests was to obtain data 
relating to the performance of a motor-compressor when operated 
in the test room upon a pre-arranged schedule. Further, it 
was desired to study the relative results of different schedules 
of operation, and to compare the information thus gained with 
that already obtained from the service braking tests. 

GENERAL CONDITIONS OF THE TESTS. 

In the service tests of the motor-compressor, already de- 
scribed, the effort was made to determine the energy consump- 
tion for braking purposes under normal working conditions. 
These tests were carried on for a sufficient time and under a 
variety of conditions sufficient to yield data which are appli- 
cable to similar conditions elsewhere and to other conditions 
b}'' means of suitable modifications. It was realized, however, 
that tests of this kind, being tedious and expensive to make, 
could only be performed under exceptional conditions. Hence, 
a most important part of the plan of the braking tests consisted 
in determining the relation between stand tests and service 
tests of motor-compressors. After the elaborate service tests 
had been completed, a series of stand tests was made, which 
rendered possible a comparison between the rather artificial 
tests on the stand and the actual tests in service. These stand 
tests were made at the shops of the St. Louis Transit Company 
during November, 1904. The stand tests were divided into 
two parts: ^ 

(1.) One in which the coriipressor was allowed to pump against 
a fixed pressure. 

(2.) One in which service conditions were imitated as closely 
as possible. 

WORKING UP THE RESULTS. 

The data resulting from the tests were entered on a "Com- 
bined Log Sheet," as in the preceding tests. The electrical 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 315 

data were checked by comparison of the readings of the watt- 
hour meter and the voltmeter and ammeter. The watt-horn* 
meter was cahbrated for these tests. 

The measuring reservoir pressures for all runs were averaged 
before and after the operation of the compressor, giving data 
from which, with due allowance for temperature and baro- 
metric pressure, the volume of air corresponding to each run 
was calculated. The temperatures of motor armatures and 
fields were obtained by means of thermometers and by mea- 
surements of the resistances of the circuits. By this means it 
was possible to secure an accurate check upon the temperature 
measurements. From the change in resistances of the arma- 
tures and fields, the average temperature throughout the 
machine was secured. From the thermometers, the surface 
temperatures were obtained. 

The results of the entire number of runs, comprising the 
series, were averaged, and from these averages the summary, 
as given in Table LI, was made. 

DESCRIPTIONS AND RESULTS OF THE STAND TESTS. 

Test No. 26. Compressor Pumping against Ninety Pounds 

Pressure. 

The plan employed in Test No. 26, in which the compressor 
was allowed to pump against a constant pressure, was that 
suggested by Mr. E. H. Dewson in the Street Railway Journal, 
Vol. XXIII, No. 9, page 320, February 27, 1904. The elec- 
trical apparatus was arranged as in the car test, except that 
the circuits were connected as in Fig. 88, for resistance mea- 
surements. The compressor was allowed to pump into a small 
receiving reservoir of approximately three cubic feet capacity, 
the air entering at the side of the reservoir. This was equipped 
with a pressure gage reading above 90 lbs. A similar reservoir, 
with a capacity of 4.742 cu. ft., was connected to the smaller 
one by means of a pipe containing a three-way valve and a 
needle valve. The function of the needle valve was to adjust 
the pressure against which the compressor was allowed to 



316 



ELECTRIC RAILWAY TEST COMMISSION- 



pump, while that of the three-way valve was to alternately 
connect the small or measuring reservoir with the receiving or 
supply reservoir and with the exhaust. In other words, with 
the three-way valve in one position, air was delivered from the 
suppl}^ to the measuring reservoir. In the other position the 
measuring reservoir was disconnected from the supply reser- 
voir and was open to the air, thus reducing the measuring 
reservoir pressure. The large reservoir was also equipped with 
a pressure gage. 

TROLLEV 



MILU -AMMETER 




Fig. 86. — Connections for Resistance Measurements, Stand Test of Motor-Compressor. 

In the compressor circuit were an indicating ammeter and 
voltmeter, and a recording watt-hour meter. A revolution 
counter was also connected to the compressor so that the total 
number of double strokes was recorded. Thermometers were 
placed at various parts of the motor and compressor, and were 
read from time to time to determine the rise in temperature. 
Measurements of the resistances of the armatures and fields 
were also made periodically. 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 317 

The operation of the tests consisted in maintaining a uni- 
form pressure of 90 lbs. per square inch in the large reservoir 
by manipulation of the needle valve, the measuring reservoir 
pressure being reduced periodically. At a given signal the 
compressor motor was started and a uniform pressure was 
maintained in the large reservoir as described above, the three- 
way valve being open so as to connect the two reservoirs. 
The air was allowed to flow at this constant pressure for a 
period of one minute, the pressure in the measuring reservoir 
increasing about 27 lbs. during this time. The motor com- 
pressor was then stopped, and the air pressure in the measur- 
ing reservoir was reduced. After three minutes had elapsed 
from the time of start, the operation was repeated. This was 
kept up for several hours, imtil the temperature of the motor 
had attained a steady value. 

The measuring reservoir pressures varied between values of 
44.70 and 72.01 lbs. per square inch, a range of 27.31 lbs. 

The results of Test No. 26 are shown in Table LI. 

Tests Nos. 27 and 28. Compressor Pumping from 45 lbs. to 52J 
and 62-2- Ihs., Respectively. 

These tests were designed to imitate as closely as possible the 
service tests made upon the cars. In order to determine the 
effect of setting the governor at different upper limits the latter 
was placed at 52 J lbs., representing the minimum in ordinary 
service, and at 62J lbs. representing the high service reservoir 
pressure. These two tests, therefore, gave data correspond- 
ing very closely to the conditions of the service tests. 

The apparatus used was set up in the shops of the St. Louis 
Transit Compan}^, and the various parts were connected sub- 
stantially as when located upon the car. The duration of the 
runs and the interval between starts were chosen to correspond 
with those of the service tests as nearly as possible. In Test 
No. 27 the runs were 11.4 seconds in length, and the average 
interval from start to start was 126 seconds. The correspond- 
ing intervals for Test No. 28 were 25.8 seconds and 269 seconds 



318 



ELECTRIC RAILWAY TEST COMMISSION 



respectively. As in the preceding case, the tests were continued 
until the motor had attained a stationary temperature. The 
arrangement of electric circuits and of electrical instruments, 
as well as of pressure gages and revolution counter, were exactly 
similar to the tests made upon the car, and a standard car reser- 
voir was used to receive the air from the compressor. As in 
the other case, the volume compressed was calculated from the 
rise in pressure of the air in the measuring reservoir. 

The results of these tests are given in detail in Table LI. 



Table LI. — Tests Nos. 26, 27, and 28. General Summary of Results. 



Total interval of test, hours 

Total running time, hours 

Total number of compressor runs ; . . . 

Interval of compressor run, start to start, 
min 

Interval of compressor run, start to stop, 
min 

Average temperature of outside air, degrees C. 

Average temperature of air in tank, degrees C. 

Average temperature compressor exhaust . . 

Average current, amperes 

Average e. m. f., volts 

Average power, watts 

Average power, e. h. p 

Total energy supplied, watt-hours 

Average speed of compressor shaft, r. p. m. 

Reservoir pressure before runs, lbs. per sq. in. 

Average measuring reservoir pressure after 
runs, lbs. per sq. in 

Average rise in pressure in measuring reser- 
voir during runs, lbs. per sq. in 

Average service reservoir pressure, lbs. per 
sq. in 

Temperature motor case (bolt hole) at be- 
ginning of test, degrees C 

Average temperature motor case (bolt hole) 
at end of test, degrees C 

Average rise in temperature motor case (bolt 
hole) above air temperature, degrees C. . . 

Average temperature of gear case at begin- 
ning of test, degrees C 

Average temperature of gear case at end of 
test, degrees C 

Average rise in temperature above air tem- 
perature gear case, degrees C 



Test 26. 



6.95 

1.93 

116 

5.15 

1.00 

13.4 
17.4 
55.0 
3.42 

537.2 

1,840 
2.47 

3,552 
219 

44.70 

72.00 
27.30 
93.00 
13.5 
24.0 
12.0 
11.0 
41.0 
29.0 



Test 27. 



4.95 

.442 

141 

2.10 

.190 

13.4 

15.1 

26.7 

3.12 

546.1 

1,705 

2.29 

754 

242 

43.52 

50.78 

7.26 

47.15 

12.8 

17.4 

2.8 

10.2 

22.0 

7.4 



Test 28. 



7.11 

.68 

95 

4.49 

.43 

17.6 
19.9 
31.2 
3.19 

548.0 

1,750 
2.34 

1,187 
250 

43.48 

60.59 

17.11 

52.05 

14.5 

22.7 

4.3 

14.5 

28.7 

10.3 



BRAKING TESTS AND DOUBLE-TRUCK CITY CAR 319 

Table LI. — Continued. 





Test 26. 


Test 27. 


Test 28. 


Average temperature motor field at begin- 
ning of test degrees C 


12.0 

58.0 

46.0 

13.5 

55.0 

43.0 

14.0 

46.0 

34.0 
970 

8.36 

3.66 

.243 

.295 


10.9 
34.0 
19.4 
11.1 
38.0 
23.4 
10.0 
25.0 

10.4 

328 

2.32 
2.30 
.383 

.185 


14 3 


Average temperature by resistance of motor 
field at end of test degrees C 


32 


Average rise in temperature by resistance, of 

motor field above air temperature, degrees C. 
Average temperature of motor armature at 

beginning of test, degrees C 

Average temperature by resistance of motor 

armature at end of test, degrees C 

Rise in temperature above air temperature, 

of motor armature degrees C 


13.6 

14.7 
74.0 
55 6 


Average temperature of motor commutator 
at beginning of test degrees C 


15 


Average temperature of motor commutator 
at end of test degrees C 


30.0 


Average rise in temperature of motor com- 
mutator above air temperature, degrees C. 

Total volume of free air compressed, cu. ft. 

Average volume of air compressed per run, 
cu. ft 


11.6 

488 

5.14 


Energ)^ per cu. ft. of free air compressed, 
watt-hours 


2.43 


Weight of air delivered by compressor per 
H. P. minute 


.363 


Power to compress to above pressure, one cu. 
ft. free air per minute, E. H. P 


.195 



Discussion of the Results of the Air Braking Tests Nos. 22 to 29. 

The tests described in this chapter of the Report covered a 
wide range of operating conditions, and they were numerous 
enough to assure accuracy in the results. The tests were con- 
tinued over periods of time sufficient to include braking service 
in all parts of the day. Every quantity which could have any 
bearing on the test was measured, and its effect on the results 
was allowed for in working up the data. It is therefore safe 
to draw certain general conclusions from the data obtained. 

Comparison of the Storage and Motor-Compressor Systems. 

Table XL shows that the two storage tests, Nos. 22 and 23, 
and the two motor-compressor tests, Nos. 24 and 25, are in 
substantial agreement with each other, but that a number of 



320 ELECTRIC RAILWAY TEST COMMISSION 

marked differences appear between the results of the two groups 
of tests. The electrical energy required to compress a cubic 
foot of air is 5.49 watt-hours in the storage system and 3.99 
watt-hours in the motor-compressor system, a difference in 
favor of the latter of 37.5 per cent. This results from the greater 
efficiency of the process of compressing the air directly to the 
pressure at which it is to be used. In compressing first to a 
high pressure, w^hich is afterward to be reduced by expansion 
without useful return, a certain amount of work is done on the 
air which is absolutely lost. Further, in compressing the air 
to a high pressure a great deal of heat is generated which is 
abstracted by the cooling water and is wasted. The efficiency 
of the large motors used in the storage system is much higher 
than that of the small motors, but this is an item of minor 
importance compared with the losses in the air. This differ- 
ence in the amount of energy absorbed by the air might easily 
have been greater than shown, as is evident from an inspec- 
tion of the performance of the same motor-compressor when 
on the car and on the stand. The efficiency of compression, 
as indicated by the number of watt-hours per cubic foot of air 
compressed, is much higher in the latter case, showing that it 
would have been possible to still further improve the perfor- 
mance of the motor when mounted under the car. The results 
may, therefore, be considered as entirely conservative. 

The difference between the electrical energy used for braking 
in the two cases shows practically the same advantage in favor 
of the motor-compressor system. In the comparison based on 
brake applications, a still more marked difference exists, but as 
the relation of the number of brake applications to the number 
of stops is largely a personal matter with the motorman and is 
not a fixed quantity, no general conclusion can be based upon 
this relation. 

A more marked advantage to the motor-compressor system 
appears from an examination of the figures for energy consump- 
tion in braking per car-mile, per car-hour, and per ton-mile. 
In these cases the difference is from 50 per cent to 70 per cent. 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 321 

This follows from two causes: (1) the air is more economically 
compressed, and (2) the air is delivered more economically to 
the brake cylinders. The first of these items has already been 
discussed. The second is evident from the figures given for 
the volumes of free air used per car-hour, per car-mile, and per 
ton-mile. In the storage system more air is required from the 
fact that it is carried on the car at a high pressure, and leakage 
is difficult to avoid. This leakage occurs not only in the joints 
upon the car, but at the time of charging the amount of air in 
the charging hose is wasted. 

The results of these tests are summed up in the figures for 
the ratios found at the bottom of Table XL. It is there showii 
that while a horse-power minute of electrical energy will de- 
liver 0.155 lb. of air in the storage system, this same energy 
will compress 0.228 lb. in the motor-compressor system, this 
saving resulting from the saving in the work done on the air in 
compression and not restored to it in expansion. Similarly it 
requires 0.463 horse-power to compress one cubic foot of air 
per minute to the higher pressure, and 0.317 horse-power to the 
lower pressure. 

Finally, 1.72 per cent of the energy supplied to the car motors 
must be used for braking when the storage system is used and 
0.99 per cent with the motor-compressor, the former being 
74 per cent greater than the latter. In deciding upon the sys- 
tem to be used in any case, therefore, the question at issue is 
whether or not there is a saving in interest and maintenance 
in the use of the storage system w^hich will offset the greater 
efficiency following from the use of the other equipment. 

Comparison of the Two Storage System Tests, Nos. 22 and 23. 

While Test No. 22 was conducted upon the entire number 
of cars in operation during 24 hours and Test No. 23 covered 
but one car for a shorter period, there is substantial agreement 
in the results of the two tests. The important difference from 
the operating standpoint in the conduct of the two tests was 
that a number of the cars lay in the barn during a considerable 



322 ELECTRIC RAILWAY TEST COMMISSION 

part of the day, being used as "extras" for a few trips each. 
The leakage during this period is charged against the cars. 
That this caused no serious discrepancy in the results is evi- 
dent from the fact that while somewhat more air was used per 
car-hour in Test No. 22, slightly less was used per car-mile. 
On the whole, somewhat more air was used in Test No. 22, 
but this is accounted for by the leakage mentioned, which was 
not an important item. The ratio of braking energy to car- 
motor energy was practically unity. 

Comparison of the Several Stand Tests. 

As has been previously described, the three stand tests were 
intended to yield data as to performance under standard test 
conditions as suggested by Mr. Dewson, and under conditions 
approximately those of ordinary service. The results show, in 
all cases, a consistent increase in the energy consumption with 
'increase in the pressure pumped against. From these figures 
it is possible to predict the amount of energy that will be used 
under other circumstances. 

Comparison of Stand and Service Tests of Motor-Compressor. 

As would be expected, the motor-compressor exhibited a 
somewhat better performance upon the stand than when imder 
the car. While every precaution was taken to insure condi- 
tions as nearly similar as possible, the fact still remains that, 
with all leakage eliminated, with dirt and jar absent, and with 
regular and careful handling of apparatus, better results should 
be secured. It will be remembered that upon the car it was 
necessary to cut off the current whenever the motorman used 
air, in order to prevent a quantity of air from being used 
unmeasured. Thisfrequently necessitated abnormally short com- 
pressor runs with consequent lowering in efficiency of opera- 
tion. In addition, it was possible to read instruments more 
accurately in the shop. These features, in addition to the prin- 
cipal one of the difference in operating conditions, explains the 
better performance of the motor-compressor upon the stand 



BRAKING TESTS ON A DOUBLE-TRUCK CITY CAR 323 

The stand test may be taken as the ideal performance of the 
equipment which would be reached upon the car if all condi- 
tions were perfect. 

Comparison of Air Consumption by Trips in Tests Nos. 23, 24, 

and 25. 

Tables XL VII, XLIX, and L show in an interesting manner 
the effect of density of traffic upon the air consumption. These 
tables do not cover the entire test in any case, but the trips at 
the beginning and end of the day have been omitted, and round 
trips from and to the Tower Grove Park loop have been ar- 
ranged for comparison. In general there is a greater consump- 
tion of air in the middle of the day on account of the large 
number of stops. 



CHAPTEE IX. 

BRAKING TESTS ON AN INTERURBAN CAR EQUIPPED 

WITH AIR BRAKES. 



Objects of the Tests. 
The primary object of these tests was to determine the rates 
of deceleration which can be employed in braking a heavy 
interurban car from various speeds, and with different air 
pressm^es in the brake cylinder. 

Synopsis of Results. 

Table LII. — Synopsis of Results. Braking Tests of Interurban Car. 



Air pressure applied to brakes, lbs. per 
sq. in 

Speed at application of brakes, m.p.h. . . 

Duration of braking period, seconds . . . . 

Distance covered during braking period, 
feet 

Average deceleration, m.p.h. per sec. . . . 

Maximum deceleration, m.p.h. per sec. 

Average pressure of brake shoes on 
wheels, pounds 

Limit of braking force, at 25 per cent 
adhesion, pounds 

Average braking force from actual de- 
celeration, pounds 

Average braking force per ton from 
actual deceleration, pounds 

Average deceleration per 1000 lbs. pres- 
sure applied by brake shoes, m.p.b. 
per seconds 

Electrical energy equivalent of air used 
in making stops, watt-hours 

Weight of car 79,330 
324 



Test Numbers. 



29 



20 
44.2 

28.7 

955 
1.54 
2.20 

25,125 

19,883 

5,560 

140.3 

0.0613 
5.5 



30 



20 
53.5 

38.7 

1,540 
1.38 
2.70 

25,125 

19,883 

4,980 

125.7 

0.0550 
7.6 



31 



30 
47.2 
25.0 

932 
1.89 
3.20 

37,687 

19,883 

6,830 

172.2 

0.0502 
9.7 



32 



40 
48.8 
17.5 

655 
2.79 
4.80 

50,250 

19,883 

10,080 

254.2 

0.0555 
10.3 



33 



40 
55.5 
23.4 

985 
2.37 
3.10 

50,250 

19,883 

8,550 

216.0 

0.0471 
11.6 



lbs., 39.67 tons. 



i 



BRAKING TESTS ON AN INTERURBAN CAR 325 

General Conditions of the Tests. 

The braking tests upon the interurban car were made upon 
the stretch of tangent track between Noblesville and Carmel, 
Indiana, on the Northern Division of the Indiana Union Trac- 
tion Company's Hnes. This was the track used in the accel- 
eration tests upon the same car, and the tests were conducted 
between poles Nos. 10,909 and 10,850, the section covered during 
the braking period being absolutely level and tangent. 

The car employed in these tests was the one used in the ser- 
vice and acceleration tests already described. The details of 
the car are given fully in Chapter I. The car equipped and 
ready for service weighed 74,530 lbs., and the total weight 
under the conditions of test was 79,330 lbs., or approximately 
39.66 tons. The load was the same as in the service tests 
described in Chapter IV. As previously stated, the braking 
equipment consisted of a motor-driven compressor of the West- 
inghouse Traction Brake Company, supplying air to a 10-in. 
brake cylinder through the "straight air" system of control. 
The brake lever ratio was four to one, and the brakes were inside 
hung. 

General Description of the Tests. 

The tests consisted essentially in bringing the car to the 
desired speed, in allowing it to drift a distance of 500 ft., and 
in applying the brakes with a pre-determined air pressure which 
was maintained constant until the car came to rest. The time 
available for this test was not sufficient to permit of a great 
range of speed, and it was therefore deemed advisable to study 
braking conditions from the ordinary speeds at which this car 
would be normally operated. Speeds were selected ranging 
between 45 miles an hour and 56 miles an hour. The brake 
cylinder pressures employed in the tests ranged from 20 to 40 
lbs.; these limits being chosen as covering the requirements of 
ordinary practice, and giving data from which the effect of 
employing other pressures could be readily predicted. 

In connection with the braking tests, readings were made to 



1^ 



326 ELECTRIC RAILWAY TEST COMMISSION 

determine the electrical energy equivalent to the air used. The 
pressure in the storage reservoir was noted at the beginning 
and at the end of each application. By means of an auxiliary 
test, made to determine the relation between the electrical 
energy used and the volume of air compressed, it was possible 
to ascertain the relation desired. 

ORIGINAL MEASUREMENTS. 

The recording apparatus, installed upon the car for the pur- 
pose of making the service tests already described, was also 
employed in the present series of tests. 

Speed and Distance Measurements. 

The speed of the car was accurately determined by means 
of an "Apple" generator connected with the car axle by 
a sprocket chain, a voltmeter being connected to the arma- 
ture of the generator. The indications of the voltmeter were 
checked by the pole record made on the recording mechanism, 
the instant of passing each pole being shown on a time base. 
The distance from the last pole to the actual point of stop was 
measured by means of a steel tape. 

Air Pressure Measurements. 

Accurate gages were connected to the piping leading to the 
air brake cylinder and to that connected with the storage reser- 
voir, and from these gages the corresponding pressures were 
determined. 

Electrical Measurements. 

In order to determine the electrical energy expended in brak- 
ing under various conditions, an independent series of tests was 
made on the motor-compressor. The calibration consisted 
essentially in the determination of the quantity of electrical 
energy expended in applying the brake under the same condi- 
tions of brake cylinder pressure and time interval of the braking 
period, as occurred in the braking tests. A series of observa- 
tions was made for each condition, readings being obtained 



BRAKING TESTS ON AN INTERURBAN CAR 



327 



showing the initial and final pressures in the reservoir, the 
brake cylinder pressure, and the duration of the application 
in seconds. The electrical energy required to restore the reser- 
voir pressure was ascertained by inserting a watt-hour meter 
in the motor-compressor circuit and making a series of runs of 
the motor-compressor, pumping within the desired limits. The 
results showed an energy consumption of 2.1 watt-hoiu"s per 
pounds variation of pressure in the reservoir. Investigations were 
made at braking pressures of 20, 30, 40 and 50 lbs. The dura- 
tion of the application of the braking pressure varied from 15 to 
44 seconds, and covered all of the conditions employed in the 
braking tests. The governor controlling the pressure was set 
for a lower limit of 58, and an upper limit of 71 lbs. The gen- 
eral results of this calibration have been arranged, for conve- 
nience, in tabular form as follows: 

Calibration Data of Motor-Compressor and Air Brakes. 



Brake cylinder pressure, pounds 

Average duration of brake application, seconds 

Average fall in reservoir pressure, pounds 

Electrical energy per pound variation in reser- 
voir pressure, watt-hours. 

Electrical energy per brake application, watt- 
hours. 

Upper limit of reservoir pressure, pounds 

Lower limit of reservoir pressure 

Average number brake applications for one 
pumping. 



20 


30 


40 


35 


25 


23 


3.3 


4.6 


4.9 


2.1 


2.1 


2.1 


6.9 


9.7 


10.3 


71 


71 


71 


58 


58 


58 


5.0 


3.5 


2.5 



50 

15 

6.3 

2.1 

13.2 

71 

58 
2.0 



The data showing the electrical energy equivalent to the air 
used in making stops, under various conditions of braking, are 
given in Table LII. The calculations are based upon the original 
data showing the actual fall in reservoir pressure during each 
test, the results given above in tabular form being employed 
in the proper interpretation of the original data. In this con- 
nection it should be observed that leakage tests were also made 
at the same time that the calibration tests were performed. 
These investigations show a fall of approximately one pound 
per minute in the reservoir pressure, due to leakage, within 
the limits of pressure employed in the braking tests. 



328 ELECTRIC RAILWAY TEST COMMISSION 

WORKING UP THE RESULTS. 

As the results of these tests were very largely obtained graphi- 
cally, the form used has been adhered to in working up the re- 
sults. After correction of the various quantities measured, 
the first step was to produce accurate time-speed and time- 
distance curves for each case, by combining the results fur- 
nished by the speed recorder and the time-distance data. By 
means of integration of the speed curves up to various points, 
the distance data obtained from the pole record were checked 
point by point. The curves represent the average values from 
two tests in most cases, which were as many as it was prac- 
ticable to make in the available time. From the time-speed 
and time-distance curves a number of deductions were made, 
including average and maximum deceleration. By combining 
with these results the air pressure data, other deductions were 
made showing the relation of the brake-shoe pressures to the 
deceleration produced thereby. 

The general results of the tests have been arranged in tabular 
form in Table LII. In preparing the table the tests were ar- 
ranged in order of air pressure. Tests Nos. 29 and 30 and Tests 
Nos. 32 and 33 form two groups, the first named in each case 
being at the lower speed. Test No. 31 stands alone, as time did 
not permit a test at higher speed and at this air pressure. 

The average deceleration was obtained by dividing the speed 
at the instant of application of the brakes by the time interval 
of the braking period. The maximum deceleration was de- 
termined by the approximate method of drawing tangents to 
the braking curve (time-speed curve), and from the slope of 
this tangent obtaining the ratio of the speed to the time. The 
accuracy of this method depends upon the correctness of the 
shape of the curve during the last few seconds of the run, and, 
as this shape is very difficult to obtain, the accuracy of the 
results of these calculations is not as great as that of the 
average deceleration, but they are as close to the correct values 
as could be obtained with the apparatus employed. 



BRAKING TESTS ON AN INTERURBAN CAR 329 

The average brake shoe pressure was obtained from the piston 
area, the air pressure, and the brake leverage. The figures 
given represent the total pressure on eight brake shoes. In 
order to determine how near these results approach to the ordi- 
narily accepted limit of braking force, this limiting value, 25 
per cent of the weight of the car, has been placed in the table 
for comparison with the results of the tests. Under these 
figures are placed the actual braking forces as calculated from 
the weight of the car and the deceleration produced. This 
braking force is simply the product of the weight of the car in 
pounds divided by 32.2, the acceleration of gravity, and mul- 
tiplied by the acceleration in feet per second per second. The 
values were calculated both for the total weight and per ton. 
The average deceleration per thousand pounds pressure upon 
the brake shoes was also calculated, in order to permit of a 
comparison of the braking effect from the various speeds and 
with the several brake-cylinder pressures. 

Finally, the electrical energy equivalent to the air used in 
making stops was determined by means of an auxiliary test, 
as already described. From the amount of electrical energy 
used in the compressor to produce a certain rise of reservoir 
pressure, a constant was deduced, which gave the electrical 
energy corresponding to that of ordinary operation, and a suffi- 
cient number of tests were made to insure reasonable accuracy 
in this deduction. 

Results of the Tests. 

The calibration runs of the motor-compressor comprised a 
sufficient variation in duration and range of pressure to secure 
an accurate average. From these tests the constant derived 
was 2.1 watt-hours as the electrical energy required to produce 
a change in reservoir pressure of one pound per square inch. 
The general results of the tests are given in the synopsis. Table 
LII, at the beginning of the chapter. For the purpose of enab- 
ling a detailed study to be made, the data showing the action 
of the car throughout the deceleration period have been placed 



330 



ELECTRIC RAILWAY TEST COMMISSION 



in graphical form, and are shown in Figs. 89 to 93, inclusive. 
The accompanying '4ogs" give the generel data of each test, 
arranged conveniently for comparison between the numerical 
and the graphical representations. 

GENERAL LOG SHEET OF BRAKING TEST NO. 29. 

Air pressure applied to brakes 20 lbs. per sq. in. 

Speed at application of brakes 44 . 2 miles per hour. 

Duration of braking period 28 . 7 seconds. 

Distance covered during braking period 955 ft. 

Average deceleration 1 . 54 mUes per hour per second. 

Maximum deceleration 2 . 20 miles per hour per second. 

Average pressure of brake shoes on wheels 25,125 lbs. 

Limit of braking force, 25 per cent adhesion 19,883 lbs. 

Average brakiug force from actual deceleration 5,560 lbs. 

Average braking force per ton from actual deceleration 140 . 3 lbs. 
Average deceleration per 1000 lbs. pressure applied by 

brake shoes 0613 miles per hour per second. 

Electrical energy equivalent of air used in making stop 5 . 5 watt-hours. 

























































































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Fig. 89. —Speed and Distance Data. Test No. 29. 



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30 







BRAKING TESTS ON AN INTERURBAN CAR 



331 



GENERAL LOG SHEET OF BRAKING TEST NO. 30. 

Air pressure applied to brakes 20 lbs. per sq. in. 

Speed at application of brakes 53 . 5 miles per hour. 

Duration of braking period 38 . 7 seconds. 

Distance covered during braking period 1,540 ft. 

Average deceleration 1 .38 miles per hour per second. 

Maximum deceleration 2 . 70 miles per hour per second. 

Average pressure of brake shoes on wheels 25,125 lbs. 

Limit of braking force, 25 per cent adhesion 19,883 lbs. 

Average braking for actual deceleration 4,980 lbs. 

Average braking force per ton, from actual deceleration 125 . 7 lbs. 
Average deceleration per 1000 lbs. pressure applied by 

brake shoes 0550 miles per hour per second. 

Electrical energy equivalent of air used in making stop 7 . 6 watt-hours. 



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Fig. 90. — Speed and Distance Data. Test No. 30. 



40 







GENERAL LOG SHEET OF BRAKING TEST NO. 31. 

Air pressure applied to brakes 30 lbs. per sq. in. 

Speed at application of brakes 47 . 2 miles per hour. 

Duration of braking period 25 . seconds. 

Distance covered during braking period 932 ft. 

Average deceleration 1 . 89 miles per hour per second 

Maximum deceleration 3.2 miles per hour per second. 



332 



ELECTRIC RAILWAY TEST COMMISSION 



Average pressure of brake shoes on wheels 37,687 lbs. 

Limit of braking, force 25 per cent adhesion 19,883 lbs. 

Average braking force from actual deceleration 6,830 lbs. 

Average braking force per ton, from actual deceleration 172 . 2 lbs. 
Average deceleration per 1000 lbs. pressure applied by 

brake shoes 0502 miles per hour per secondc 

Electrical energy equivalent of air used in making stop 9 . 7 watt-hours. 



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Fig. 91. — Speed and Distance Data. Test No. 31, 



25 







GENERAL LOG SHEET OF BRAKING TEST NO. 32. 

Air pressure applied to brakes 40 lbs. per sq. in. 

Speed at application of brakes 48 . 8 miles per hour. 

Duration of braking period 17.5 seconds. 

Distance covered during braking period 655 ft. 

Average deceleration 2 . 79 miles per hour per second. 

Maximum deceleration 4.80 mUes per hour per second. 

Average pressure of brake shoes on wheels 50,250 lbs. 

Limit of braking force, 25 per cent adhesion 19,883 lbs. 

Average braking force from actual deceleration 10,082 lbs. 

Average braking force per ton, from actual deceleration 254 . 2 lbs. 






BRAKING TESTS ON AN INTERURBAN CAR 333 

Average deceleration per 1000 lbs. pressure applied by 

brake shoes 0555 miles per hour per second. 

Electrical energy equivalent of air used in making stop 10.3 watt-hours. 



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18 







GENERAL LOG SHEET OF BRAKING TEST NO. 33. 

Air pressure applied to brakes 40 lbs. per sq. in. 

Speed at application of brakes 55 . 5 miles per hour. 

Duration of braking period 23 . 4 seconds. 

Distance covered during braking period 985 ft. 

Average deceleration 2 . 37 miles per hour per second. 

Maximum deceleration 3. 10 miles per hour per second. 

Average pressure of brake shoes on wheels 50,250 lbs. 

Limit of braking force, 25 per cent adhesion 19,883 lbs. 

Average braking force from actual deceleration 8,550 lbs. 

Average braking force per ton, from actual deceleration 216 . lbs. 
Average deceleration per 1000 lbs. pressure applied by 

brake shoes 0471 miles per hour 

Electrical energy equivalent of air used in making stop 11.6 watt-hours. 



334 



ELECTRIC RAILWAY TEST COMMISSION 



































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Fig. 93. — Speed and Distance Data. Test No. 33. 



25 



Discussion of Results. 

The results as shown in Table LII, cover braking from the 
ordinary speeds at which the particular type of car would be 
operated in ordinary service. The tests show that with an aver- 
age pressure of from 20 to 40 lbs. in the brake cylinder it is 
possible to secure decelerations of between 1.5 and 2.5 miles 
per hour per second, while the corresponding average length 
of stop will be somewhat under 1000 ft. In all cases the aver- 
age rate of deceleration is smaller at the higher speeds than it is 
at the lower values of speed. This indicates that at the high 
speeds the brake shoes do not take hold of the wheels as quickly 
as they do at the lower speeds. As would be expected, the 
maximum deceleration, which occurs during the last few sec- 
onds of the braking period, is considerably greater than the 
average, and while the figures for these values do not warrant 



BRAKING TESTS ON AN INTERURBAN CAR 335 

any sweeping deductions, they show that the maxiniiun exceeds 
the average value by from 50 to 75 or more per cent. This 
increase in deceleration toward the end of the braking period 
is due to the increase in friction between the brake shoes and 
the wheels at the low speeds. 

Assuming that the wheels would "skid" when the braking 
force is about 25 per cent of the weight of the car, the table 
shows that in no case in these tests did the actual braking force 
approach this limit. In fact in the extreme case shown. Test 
32, the braking force is only slightly more than 50 per cent of 
the theoretical limit. This means that it would have been 
possible in an emergency, to have stopped the car with a braking 
force twice that actually employed in this case. The braking 
force in pounds per ton varies in the tests from 125.7 lbs. to 
254.2 lbs., which forces produced rates of deceleration closely 
corresponding to those which would be expected from the pres- 
sure applied to the brake shoes. In order to study this rela- 
tion somewhat more closely, the values of deceleration produced 
by each thousand pounds applied to the brake shoes have been 
entered in the table. These figures show that the deceleration 
produced per unit of brake-shoe pressure is greater at the lower 
cylinder pressures, although the results of Test No. 31 do not 
accord with the general rule. However, the fact that the value 
shown in Test No. 29 is considerably higher than in Test No. 32, 
while in Test No. 30 it is higher than in Test No. 33, fully war- 
rants the deductions drawn. 

The data showing the amount of electrical energy required to 
compress a volume of air s\ifRcient to bring the car to rest from 
the various speeds,. may be compared with the results obtained 
in the city car tests, as given in Table XL. In Tests Nos. 32 
and 33, which correspond most nearly with the conditions of 
the preceding tests, approximately 10.9 watt-hours are used 
per stop. Comparing these figures with those for the motor- 
compressor given above, it is noted that the amount of air, while 
greater in the interurban tests, is not in proportion to the speed 
from which the stop is made. As a matter of fact, it should 



336 ELECTRIC RAILWAY TEST COMMISSION 

not be so, as after the brakes have been once applied, only- 
enough air is needed to make up for the leakage. As the dura- 
tion of the braking period is greater with the interurban car, the 
possibility of leakage is correspondingly increased. 

The Graphical Results. 

Figs. 89 to 93, inclusive, show curves of speed, deceleration, 
and distance traversed during the braking period, for Tests 
Nos. 29 to 33, inclusive. 

As previously stated, the data shown represent the average 
of two runs for each test. The speed curves were obtained 
graphically in taking the original data, in a manner similar to 
that employed in obtaining the speed data for the service runs 
on the interurban car. The general method employed and the 
apparatus used were described in Chapter II. It will be noted 
that all of the diagrams are represented on a time base. While 
the interval of deceleration varied considerably in the five tests, 
the limiting values were between 17.5 and 38.7 seconds. This 
large variation in the time necessary to bring the car to a stop 
is due to two reasons : first, the speed at the instant of the appli- 
cation of the brakes was not the same in all tests; and, second, 
the braking pressure was varied in the different tests. 

The Speed Curves. — The speed curves have the same gen- 
eral form in all of the tests, although the speed at the instant 
the brakes were applied varied from 44.2 miles per hour to 55 
miles per hour. The speed fell off at practically a uniform rate 
throughout the entire braking period, excepting during the very 
last portion of this interval. In all of the tests the car was 
permitted to drift 500 ft. before the brakes were applied. This 
resulted in a slight deceleration during the interval just previous 
to the application of the brakes. 

The Deceleration Curves. — The deceleration curves 
show an abrupt increase from a deceleration of approximately 
0.25 of a mile per hour per second at the instant of the applica- 
tion of the brakes, to a practically constant deceleration which 
lasted throughout the greater portion of the braking period, 



BRAKING TERTS ON AN INTERURBAN CAR 337 

again rising somewhat abruptly during the last few seconds of 
the interval. It was impossible to accurately determine the 
exact value of the deceleration due to the period of drifting 
immediately preceding the application of the brakes, but it was 
approximately 0.25 of a mile per hour per second. This value 
has been taken as the deceleration at the instant of the appli- 
cation of the brakes. The average deceleration varied from 1.38 
miles per hour per second in Fig. 90, to 2.79 miles per hour per 
second in Fig. 92. This difference is due to the variation in the 
air pressure applied to the brakes. This pressure was 40 lbs. 
per square inch in Fig. 92, as against 20 lbs. per square inch in 
Fig. 90. 

The Distance Curves. — While the distance curves have 
the same general shape in all of the diagrams, it is seen that the 
distance traversed varies considerably in the several tests, 
ranging from 655 ft. in Fig. 92, to 1540 ft. in Fig. 90. This 
variation in the distance traversed during the braking interval 
is due to differences both in the air pressure during the braking 
interval, and in the speed of the car at the instant the brakes 
were applied. The results, while differing considerably in the 
various tests, are within the limits shown in Figs. 90 and 92. 



CHAPTER X. 

BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 
EQUIPPED WITH MAGNETIC BRAKES. 



Objects of the Tests. 

These tests were made to determine the braking curves of a 
car equipped with magnetic brakes when the brake controller 
was operated in various ways. It was desired to determine the 
most effective method of handling this brake, the object being 
to produce a quick and smooth stop without undue heating of 
the motors. 

Synopsis of Results. 



Table LIII. — Synopsis of Results. Braking Tests of a Single-Truck City 
Car Equipped ir.ith Magnetic Brake. 

(Each datum is the average of fifty runs.) 



Average duration of braking period, seconds 

Average distance covered during braking period, feet 

Average speed at application of brakes, M.P.H 

Average speed during braking period, M.P.H 

Average deceleration during braking period, M.P.H. per second .... 

Average deceleration during last second, M.P.H. per second 

Average total braking force calculated from actual deceleration, lbs. 

Average braking force per ton, from actual deceleration, lbs 

Average current during braking, amperes 

Average maximum current during braking, amperes 

Average time to maximum current during braking, seconds 

Average square root of mean square current during braking, amperes 
Average ratio of average current to square root of mean square current 

Average E.M.F. during braking, volts 

Average maximum E.M.F. during braking, volts 

Average quantity of electricity passing through brake circuits, 

ampere-seconds 

Average electrical energy delivered by motors acting as generators, 

watt-hours 

Average ampere-seconds per M.P.H. per second of average deceleration 



7.13 

114.67 

18.15 

10.91 

2.57 

3.49 
3,356 
233.9 
135.6 
241.6 

1.61 
154.3 

1.16 
155.8 
345.4 

945.5 

39.5 
372 



338 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 339 

General Conditions of the Tests. 

All of the braking tests upon the single-truck car were car- 
ried out on the tracks provided for the Electric Railway Test 
Commission by the Louisiana Purchase Exposition Compan}^ 
These tracks were approximately 1200 ft. in length, and were 
located parallel to and directly north of the Transportation 
Building at the St. Louis Exposition. The braking tests were 
conducted on the north one of these tracks, which was tangent 
and level throughout the entire length used. 

The car selected for these tests was the same single-truck car 
used in making the service tests considered in Chapter II, and 
is fully described and illustrated in Chapter I. The car equipped 
and ready for service weighed 24,665 lbs., and the total weight 
under the conditions of test was 28,715 lbs., or approximately 
14.3 tons. The load was the same as in the service tests of 
Chapter 11. 

The car was equipped with a magnetic brake of the Westing- 
house Traction Brake Company, manufactured under the 
Newell patents. In this system the brake comprises a track 
shoe combined with an electro-magnet which, when energized 
by current produced by the motors acting as generators, is 
magnetically attracted to the track, producing four effects: 

(1) An increase in the pressure of the wheels upon the track. 

(2) A retardation due to the friction between the track shoes 
and rails. 

(3) A braking effect on the wheels due to the transmission 
of the resultant drag of the track shoes to the brake shoes by 
means of suitable levers. 

(4) A back torque in the motors which act as generators, 
supplying current to the magnets. 

These effects combine to produce a braking effort which is not 
only a powerful one, but which has certain peculiar character- 
istics not common to hand or air brakes. 

The magnetic track brake consists of three essential parts: 
(1) An electro-magnet equipped with steel track shoes which 



340 



ELECTRIC RAILWAY TEST COMMISSION 



form the poles; (2) a system of levers for transmitting the brak- 
ing force to the wheel brake shoes; and (3) an electrical regu- 
lative device for controlling the electromotive force, which can 
be furnished by the car motors acting as generators. 

The construction of the brake and rigging is shown in Figs. 
94, 95, and 96. Fig. 94 shows a view of the braking equipment 
taken from imder the car, at a point midway between the 
trucks. Fig. 95 represents a transparent view, showing the 




Fig. 94. — General View of Braking Equipment Taken from under the Car. 

method of attaching the brake to the car frame and trucks; 
while Fig. 96 shows the truck frame for the magnetic brake. 
Two track brakes are employed in a single-truck car, one being 
located at the center of each side of the truck frame, and each 
is made in three parts. The magnetic circuit proper is com- 
posed of steel, and the poles are shod with replaceable soft steel 
blocks. These steel shoes are beveled off at a sharp angle in 
order to enable them to throw obstructions from the rails, and 
to ride easily over such slight irregularities in the rails as are 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 341 

not sufficient to derail the car. The shoes are brought as near 
together as possible without short circuiting the magnetic flux. 
The magnetomotive force for the track brake is furnished by a 
magnet winding of sufficient cross-sectional area and radiating 




Fig. 95. — Transparent View of Braking Equipment, Showing IVIettiod of Attaching the Brakes. 

surface to carry a current of one hundred amperes or more, for a 
short period of time. The coil is inclosed in a water-proof cover 
of substantial construction, and the winding terminates in two 
insulated binding posts at the top of the coil. The coil is located 




Fig. 96. — View of Track Frame for Magnetic Brake. 

midway between the poles on a reduced section of the magnet 
core and is rigidly held in position. The bottom of the coil is 
carried several inches above the track, and is protected from 
injury by the core and pole shoes. 



342 



ELECTRIC RAILWAY TEST COMMISSION 



The track brake is flexibly suspended by adjustable steel 
springs through a bracket secured to and projecting upward 
and inward from the side frame of the truck. It clears the rail 
by a short distance when the coil is not energized. The two 
track brakes, located opposite each other, are cross-connected 
by a light steel frame so that the distance between them is rigidly 
maintained, and the desired stiffness is secured. Each side of 
the track brake is attached by means of an adjustable link, to 
the end of a lever through which the braking force is trans- 




-T'-C" Vs/xtzi. Base. — — . 

Fig. 96a. — Sketch Showing General Construction of Magnetic Brake. 

mitted to the regular wheel brake shoes. This brake rigging 
is clearly shown in the figures already referred to. 



THE CONTROLLER DEVICES. 

The general connections of the motor and resistances for the 
various power positions of the controller are shown in Fig. 54, 
Chapter V, of Part IV, under the description of the accelera- 
tion tests on this car. The controller is provided with sixteen 
notches, five of which are for the series operation of the motors 
and four for their parallel position, while the remaining seven 
notches are for the control of the magnetic brake. 

Fig. 97 is a diagram of connections showing the method of 






BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 343 



operating the magnetic brake. The general connections remain 
the same for all brake positions of the controller, the resistance 
in the circuit being diminished as the various notches of the 
controller are passed over. 

The automatic regulator, which forms an essential part of this 
system of braking, is also shown in Fig. 97. It consists essen- 
tially of a device for shimting the field current of the motors 
as the braking current increases in value. The essential fea- 
ture is a solenoid operating a plunger, which controls a sliding 
contact. The resistance of the shunt across the motor fields 
varies with the position of this contact, and thus the voltage of 




ON MOTORS 



OCONTACTS ON CONTROLLING CYLftSDER. Q CONTACTS ON BRAKE CVLlNOtR 

A CONTACTS QN REVERSING CYLINDEIR 

Fig. 97. — Wiring Diagram of Connections, Showing Operation of /Magnetic Brake 

the motor terminals is regulated. As the motors are short- 
circuited through the brake coils, and as series motors acting 
as generators are susceptible to changes in speed, the importance 
of this device is evident. The regulator is adjustable so that it is 
possible to vary the maximum voltage, and hence the maxi- 
mum current which can be drawn by the brakes, for a given 
speed. The extreme values of braking current and pressure 
generated by the motors are shown in the data following, and 
are considered in the discussion at the end of the chapter. 

General Description of the Tests. 
The general method of conducting the tests consisted in 
bringing the car to a given speed, beginning braking at a fixed 
point on the track, and then operating the controller according 



344 



ELECTRIC RAILWAY TEST COMMISSION 







•| 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 345 

to a given schedule, the time of passing from notch to notch 
of the controller being accurately determined by means of a 
stop watch, and in accordance with a predetermined schedule. 
Each run was repeated and the average of the two tests used, 
in order that the data obtained might be substantially correct. 
The automatic regulator was adjusted by representatives of the 
Westinghouse Traction Brake Company before these tests were 
performed, to conform to service conditions on a level track. 
The adjustment of the regulator remained unchanged through- 
out the braking tests. 

As the automatic regulator was not varied, there remained 
but two other general conditions which entered into the method 
of conducting the tests. These may be classified as Running 
Conditions and Method of Applying Brake. 

Running Conditions. — All rims were made from west to 
east, the start being made at a certain point near the west end 
of the upper test track. Five running conditions were em- 
ployed as follows: 

(1) Turn power on in 100 ft., run 400 ft. with full power on, 
turn off power, drift 100 ft., and apply brake. 

(2) Same as (1), but drift only 90 ft., then turn power full 
on and instantly off, and apply brake. This charges the field 
immediately before the application of the brake. 

(3) Turn power on in 100 ft., run 400 ft. with full power on, 
turn off power, and apply brake. 

(4) Same as (1), but run with full power on 300 ft., turn off 
power, drift 200 ft., and apply brake. 

(5) Same as (4), but drift 190 ft., and charge field by turning 
power on and instantly off before applying brake. 

Method of Applying Brake. — Five methods of applying 
the brake were employed, as follows : 

(1) Turn to braking notch 3, pause two seconds, and then 
advance at the rate of one notch per second. 

(2) Turn to braking notch 4^ and advance as fast as prac- 
ticable. 

(3) Turn at once to braking notch 6 until car has almost 
stopped, and then advance to the 7th notch. 



346 



ELECTRIC RAILWAY TEST COMMISSION 



(4) Turn at once to braking notch 5 until car has almost 
stopped; and then advance to the 6th and 7th braking notches. 



SCHEDULE OF RUNS. 



As there were five different running conditions and five con- 
ditions governing the method of applying the brake, a series 
of twenty-five runs in all was made. These runs are shown in 
the following schedule. 



Run. 



A .. 
B .. 
C .. 
D .. 
E .. 
F .. 
G .. 

H.. 



J.. 



K.. 



Running Conditions. 



Turn power on in 100 ft., run with fujl 

power 400 ft., drift 100 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 100 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 100 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 100 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 100 ft., and apply 

brake. 
Turn power on in 100 ft., run 400 ft., 

drift 90 ft., turn power full on and 

instantly off and apply brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 90 ft., turn power 

full on and instantly off, and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 90 ft., turn power 

full on and instantly off, and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 90 ft., turn power 

full on and instantly off, and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., drift 90 ft., turn power 

full on and instantly off, and apply 

brake. 
Turn power on in 100 ft., run with full 

power 400 ft., and apply brake. 



Method of Applying 
Brake. 



Turn to notch 3, pause two 
sec. and then advance at 
rate of one notch per sec. 

Turn to notch 4, and advance 
as fast as practicable. 

Turn at once to 7th notch. 



Turn at once to 6th notch 

until almost to stop, then 

to 7th. 
Turn at once to 5th notch 

until almost to stop, then 

to 6th and 7th. 
Turn to notch 3, pause two 

sec, and then advance at 

rate of one notch per sec. 
Turn to notch 4 and advance 

as fast as practicable. 



Turn at once to 7th notch. 



Turn at once to 6th notch 
until almost to stop, then 
to 7th. 

Turn at once to 5th notch 
until almost to stop, then 
to 6th and 7th. 

Turn to notch 3, pause two 
sec, and then advance at 
the rate of one notch per 
sec 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 347 



Run. 



Running Conditions. 



Method of Applying 
Brake. 



L .. 
M . 

N .. 

O .. 
P .. 

Q.. 
R.. 
S .. 
T .. 
U.. 

v.. 
w.. 

X . 
Y.. 



Turn power on in 100 ft., run with full 
power 400 ft., and apply brake. 

Turn power on in 100 ft., run with full 
power 400 ft., and apph^ brake. 

Turn power on in 100 ft., run with full 
power 400 ft., and apply brake. 

Turn power on in 100 ft., run with full 
power 400 ft., and apply brake. 

Turn power on in 100 ft., run with full 

power 300 ft., drift 200 ft., and 

apply brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 200 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 200 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 200 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 200 ft., and apply 

brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 190 ft., charge 

field full power, and apply brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 190 ft., charge 

field full power and apply brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 190 ft., charge 

field full power, and apply brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 190 ft., charge 

field full power, and apply brake. 
Turn power on in 100 ft., run with full 

power 300 ft., drift 190 ft., charge 

field full power, and apply brake. 



Turn to notch 4, and advance 

as fast as practicable. 
Turn at once to 7th notch. 

Turn at once to 6th notch 

until almost to stop, then 

to 7th. 
Turn at once to 5th notch 

untU almost to stop, then 

to 6th and 7th. 
Turn to notch 3, pause two 

sec, and then advance at 

rate of one notch per sec. 
Turn to notch 4 and advance 

as fast as practicable. 

Turn at once to 7th notch. 



Turn at once to 6th notch 

until almost to stop, then 

to 7th. 
Turn at once to 5th notch 

until almost to stop, then 

to 6th and 7th. 
Turn to notch 3, pause two 

sec, and then advance at 

rate of one notch per sec. 
Turn to notch 4, and advance 

as fast as practicable. 

Turn at once to 7th notch. 



Turn at once to 6th notch 

until almost to stop, then 

to 7th. 
Turn at once to 5th notch 

until almost to stop, then 

to 6th and 7th. 



ORIGINAL MEASUREMENTS. 

The original data may be divided into four general classes: 
those relating to (a) electrical input; (6) time; (c) speed; and (d) 
distance traversed. 

Electrical Measurements. 

The general method of taking electrical measurements was 
the same as that employed in conducting the service tests on 



348 



ELECTRIC RAILWAY TEST COMMISSION 



the single-truck car, excepting that the readings of the indi- 
cating instruments were taken at one-second intervals instead 
of five-second intervals. The general method of procedure was 
for one person to count the seconds aloud, making use of the 
stop watch, the readings being taken upon the signal. The 
first count was taken as the signal for start, and all readings were 
begun at this point. The counting started at the instant the 
controller was turned to the first braking position. The time 
marker and relay system employed in the service tests to show 
the five-second scores on the recording instrument, were also 
used in these tests. The connections of the magnetic brake 
circuits are shown in Fig. 97. It will be seen that the General 
Electric Company recording ammeter was placed between the 
motor fields and the magnet coils of the brakes. The total 
braking current was thus obtained on the current record. 

The principal electrical measurements made in connection 
with the braking tests were those of the total braking current, 
and the electrical pressure generated by the motors. The first- 
mentioned measurement was made by means of the General 
Electric Company recording ammeter, as described above. The 
pressure generated by the motors was obtained directly across 
the armatures of the two machines, the latter being connected 
in parallel. Voltmeter readings were taken at one-second inter- 
vals throughout the braking period. 



Time Measurements. 

In addition to the stop watch readings mentioned above, the 
total time interval elapsing from the instant the brake was ap- 
plied until the car cam.e to a standstill was noted in each case. 
Besides these time measurements, the time-marking device and 
relay system employed in the service tests considered in Chapter 
II were also used, the five-second intervals being indicated upon 
the base lines of the speed and current records. The star wheel 
of the controller was equipped with a circuit-braking device 
which was connected to the time-marking device of the record- 
ing ammeter, as in the acceleration tests of Chapter V, Part III, 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 349 

By this means the actual instant at which the controller was 
turned to a given braking notch was accurately recorded with 
reference to the five-second score marks on the recording am- 
meter record. 

Speed Measurements. 

The speed was measured by means of an "Apple" ignition 
generator, driven by the car axle in a manner similar to that 
described in the service tests of Chapter II, the chronograph 
being employed to give a graphical record of the armature 
pressure reading. The time and distance measurements were 
used as a check on the speed curves. 

Distance Measurements. 

While the point at which the braking began was in general 
fixed by the conditions of the test in each case, the exact posi- 
tion of the car at the instant the brake was applied was deter- 
mined by means of a piece of waste thrown from the car by an 
observer, at the instant the signal was given. The distance 
traversed during the period of braking was then obtained by 
measurements with a steel tape. 

In addition, the time of passing fixed points on the track 
was recorded on the base line of the speed record by means of 
a circuit-breaker carried on the bottom of the car and operated 
by wire trippers fastened to the track. The general arrange- 
ment of this apparatus is described and illustrated in Chapter 
V, Part III. 

WORKING UP THE RESULTS. 

The records of amperes passing through the motor armatures 
for the two rims of each test were first averaged so as to secure 
accurate graphical records of this current. These records were 
then transferred to rectangular coordinates on an enlarged 
scale. The maximum values of current and the time intervals 
from the point of application of the brakes to those at which 
the maximum current occurred, were obtained from the current 
diagrams. The average value of each record was obtained by 
integration. 



350 ELECTRIC RAILWAY TEST COMMISSION 

The ordinates of the current diagrams were then squared, 
and a diagram of squared current was produced for each test. 
From these diagrams the effective values of the currents were 
determined. 

Pressure Measurements. 

As no automatic pressure-measuring instrument was avail- 
able, readings of the indicating voltmeter were taken at one- 
second intervals. In plotting the results, allowance was made 
for inaccuracies in the measurements by checking them with 
the current and resistance of the circuit at the different con- 
troller positions. 

Speed and Distance Records. 

The average of the two graphical records for each test was 
obtained. These average values were carefully checked by 
means of the distance and time data which have been obtained 
independently. The distance records were obtained by actual 
tape-line measurements on the track and the durations of the 
braking periods were determined by actual measurements with 
a stop watch. The final speed and distance curves, therefore, 
are the result of the combination of several independent mea- 
surements. 

The average deceleration during the last second of braking 
was obtained graphically from the speed and distance curves. 
The average deceleration during the entire braking period, 
produced by the different methods of braking, was found by 
dividing the speed at the instant of application of the brakes 
by the time required for the stop, as determined by the stop 
watch. 

The results of all of the tests were put into graphical form 
for ofhce use, but the number is so large that they cannot all 
be presented in this report. A typical set of five diagrams has 
been selected, which shows a considerable variation in operating 
conditions. The most important data have been selected from 
the entire series of diagrams and have been arranged in tabular 
form. 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 351 

In preparing the tables of results the above-mentioned 
graphical data formed the basis for the deductions. The aver- 
age speed was obtained by the integration of the original time- 
speed curves, and by afterward correcting by comparison the 
time and distance data. Similar corrections were applied to 
the records of maximum speed. From the maximum speed the 
average deceleration was obtained by dividing by the duration 
of the braking period. As the determination of the maximum 
deceleration was very difficult, it was foimd more satisfactory 
to obtain the average deceleration for the last second. This 
was done by obtaining from the diagrams the speed one second 
before the actual stop, and dividing this value by the interval 
of one second. 

The actual braking force acting to bring the car to rest was 
calculated from the average deceleration. As in the preceding 
chapter, this was done by dividing the weight of the car in 
poimds by 32.2 (the acceleration due to gravity) and by the 
deceleration in feet per second per second. Then, by dividing 
these results by the weight of the car in tons, the braking force 
per ton was obtained. 

From the electrical data resulting from the tests, it was 
possible to obtain a relation between the strain on the motors 
and the braking effect produced. The former is indicated by 
the product of the average current and the time giving the 
quantity of electricity passing through the motors, in ampere- 
seconds. The total amount of energy developed by the motors 
in braking, was obtained by multiplying the quantity of elec- 
tricity by the average pressure, which gives an approximate 
measure of this energy. 

Finally, as a basis upon which to compare the results of the 
various tests, the ampere-seconds per mile per hour per second 
of deceleration were calculated and tabulated. 

From these detailed deductions the average values for all of 
the tests were obtained, and these have been placed in the 
synopsis at the beginning of the chapter. 



352 



ELECTRIC RAILWAY TEST COMMISSION 



Results of the Tests. 

The average of the results of all runs have been placed, for 
convenience, in the synopsis at the beginning of the chapter. 
The detailed time, speed, and distance data for the various 
runs are shown in Table LIV, while the corresponding electrical 
data are to be found in Table LV. 

The various data in these tables show the effects produced 
by operating the controller in different ways. The results have 
been arranged for convenient comparison with the schedule of 
operation which has been given earlier in the chapter. 



Table LIV. — Braking Tests of Single-Truck City Car. — Time, Speed, 

and Distance Data. 



Run 

Number. 



A 

B 

C ...... 

D 

E 

F 

G 

H 

I 

J 

K ..... 

L 

M 

N 

O 

P 

Q 

R 

S 

T 

U 

V 

w 

X 

Y 

Average 



Time, 
Sec- 
onds. 



8.6 
8.0 
7.6 
7.5 
7.6 
7.4 
7.5 
6.9 
7.0 
7.0 
6.7 
7.1 
6.3 
6.6 
6.8 
8.5 
7.7 
6.7 
7.3 
7.0 
6.9 
6.7 
6.2 
6.4 
6.3 

7.13 



Dis- 
tance, 
Feet. 



164.4 

139.2 

117.9 

125.2 

123.0 

132.6 

120.9 

109.6 

109.5 

110.4 

112.8 

108.1 

92.9 

99.3 

104.3 

163.9 

134.4 

99.7 

105.3 

107.9 

112.4 

96.6 

93.1 

93.4 

90.0 

114.67 



Maxi- 
mum 
Speed, 
M.P.H. 



19.8 
20.7 
18.7 
19.4 
18.6 
19.4 
18.2 
19.1 
18.1 
17.8 
20.8 
17.6 
17.6 
17.8 
20.1 
18.4 
18.0 
16.9 
16.0 
17.3 
17.9 
16.0 
17.0 
17.0 
15.8 

18.15 



Average 

Speed, 

M.P.H. 



13.1 
11.9 
10.6 
11.4 
11.0 
12.2 
11.0 
10.8 
10.7 
10.8 
11.5 
10.4 
10.1 
10.4 
10.5 
13.2 
11.9 
10.2 

9.8 
10.5 
11.1 

9.8 
10.2 
10.0 

9.7 

10.91 






,-^CO 



S hJ OS ^ ^ 



3.2 
2.9 
2.8 
3.4 
3.4 
4.0 
3.7 
3.0 
3.4 
3.8 
3.8 
3.6 
3.2 
3.4 
3.5 
4.1 
3.5 
3.8 
2.9 



3 
3 
3 
3 

3.8 
4.2 



3.49 






2.32 
2.59 

2.48 
2.59 
2.44 
2.62 
2.43 
2.77 
2.59 
2.54 



10 
48 
80 
72 
96 
16 
34 
52 
19 
2.48 
2.51 
2.67 
2.74 
2.66 
2.51 



2.57 



rh O "^ to 

s « « « 



o 



f^^ 



3,034 
3,385 
3,241 
3,382 
3,190 
3,425 
3,175 
3,620 
3,382 
3,320 
4,050 
3,241 
3,655 
3,555 
3,870 
2,824 
3,058 
3,292 
2,862 
3,241 
3,280 
3,485 
3,580 
3,476 
3,280 

3,356 



Brak- 
ing 

Force 
per 

Ton, 
Lbs. 



211.3 
236.0 
225.8 
236.0 
222.2 
238.5 
221.2 
252.1 
236.0 
231.4 
282.4 
225.8 
251.0 
247.5 
269.6 
196.6 
213.0 
229.5 
199.5 
225.8 
228.5 
243.0 
249.5 
242.0 
228.5 

233.9 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 353 

Table LV. — Braking Tests of Single-Truck City Car. — Electrical Data. 



M 

n 

D 

& 



A 

B 

C 

D 

E 

F 

G 

H 

I 

J 

K 

L 

M 

N 

O 

P 

Q 

R 

S 

T 

U 

V 

W 

X 

Y 

Average 



Q 
& 
o 



o 

H 



32 

59 
48 
59 
44 
62 
43 
77 
59 
54 
10 
48 
80 
72 
96 
16 
34 
52 
19 
48 
51 
67 
74 
66 
51 



2.57 



Pi m 



112 
129 
156 
132 
138 
127 
139 
167 
151 
149 
112 
143 
162 
148 
127 
93 
143 
129 
125 
127 
112 
126 
154 
142 
148 

135.6 






^< 



245 
240 
280 
230 
235 
200 
218 
316 
243 
220 
190 
215 
335 
248 
230 
205 
245 
250 
245 
235 
205 
220 
300 
250 
240 

241.6 



PS 

oO 



t/3 

Q 

o 

u 

w ;^ w 



2.8 
1.8 
0.5 
1.0 
1.6 
2.7 
0.8 
0.4 
0.9 
0.7 
2.8 



3.8 
0.9 
1.6 



1.5 
3.1 
1.8 
0.7 
0.6 
1.4 

1.61 



Eh 

P a. 



142 
154 
172 
152 
154 
143 
157 
190 
167 
161 
129 
139 
179 
166 
159 
133 
144 
149 
153 
149 
125 
138 
164 
175 
163 

154.3 



o 

o 
-0 

« 

o 



.265 
.184 
.104 
.145 
.118 
.137 
.131 
.169 
.109 
.088 
.146 
.153 
.110 
.122 
.252 
.441 
.228 
.150 
.188 
.174 
.116 
.096 
.167 
.120 
.113 



1.160 



pR 



o o 

<> 

PS 



^ 



p o 
< 



164 
148 
138 
153 
163 
221 
151 
139 
152 
139 
218 
183 
164 
152 
155 
117 
130 
148 
139 
171 
172 
164 
134 
144 
136 

155.8 



b .* to 

H £ w 

;^ W a! 



^=2 



aK 



:i a 



375 
310 
295 
290 
350 
405 
420 
320 
340 
300 
450 
455 
385 
300 
360 
290 
305 
305 
310 
315 
420 
440 
280 
305 
310 

345.4 



, O K 

W ^ p 

!^ t1 O 

W 2 < 



957 

1035 

1177 

991 

1030 

937 

1042 

1152 

1055 

1040 

748 

852 

1019 

967 

865 

787 

898 

866 

916 

886 

772 

848 

958 

910 

930 

945.5 



cc o p: 

. < w 

cu q: 04 

a M 



43.0 

42.6 

44.6 

41.0 

47.3 

53.6 

42.6 

42.2 

41.6 

28.9 

44.7 

47.0 

46.4 

40.0 

37.2 

24 

31 

35 

34 



42.0 
34.8 
38.6 
33.4 
35.2 
35.1 

39.5 



413 
400 
474 
383 
422 
384 
429 
416 
407 
409 
241 
344 
364 
356 
292 
364 
384 
344 
418 
357 
308 
318 
350 
342 
370 

372 



* Ratio of square root of mean square current to average current. 



While it has not been found practicable to represent the data 
for all of the tests in graphical form, the current, e.m.f., speed, 
and distance data for five runs have been represented graphi- 
cally in Figs. 98 to 102, inclusive. These have been selected 
as tj^pical diagrams for illustrating the performance of the 
car. The most important general data of these runs are as 
follows : • I 

Fig. 98 shows the general data of run F, which was a good 
average stop. 
Fig. 99 shows the performance for run M, where a sudden 



354 



ELECTRIC RAILWAY TEST COMMISSION 



application of the brake was made after a heavy charging of 
the field, resulting in a very quick stop. 

Fig. 100 shows the data of run P, where the current and 
pressure were very low in "building up," with a resultant very 
slow stop. 

Fig. 101 shows the data of run Q, where a heavy draft of 
current occurred with a low value of maximum pressure. A 
slow stop was the result in this case. 



§ 

I 

200 



150 



16 



14 



12 



10 



■ -3 
00 400 8 



300 6 



50 200 4 



100 2 



















































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Seconda 01234567 

fig. 98. — Braking Tests of Single-Truoli City Car. General Braking Data of Run F. 

Fig. 102 shows the performance for run T, which was some- 
what similar to run Q, but with the current more suddenly 
applied, thereby reducing the duration of the braking period. 

^ Discussion of Results. 

In studying the results of these tests, it was necessary to have 
in mind the various factors which enter into the operation of the 
magnetic brake. 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 355 



The track brake itself is a simple electro-magnet^ and after 
it has come into contact with the track, the pull or attractive 
force exerted is proportioned to the square of the magnetic 
induction. 



300 



250 



200 



150 



20 



18 



16 



14 



12 



10 



100 400 8 



300 6 



50 200 4 



100 2 









































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Fig. 99. — Braking Tests of Single-Trueli City Car. General Braking Data of Run M. 



For low values of the magnetizing current, the magnetic 
induction is practically proportional to the current so that the 
tractive effort would vary as the square of the current increases. 



356 



ELECTRIC RAILWAY TEST COMMISSION 



However, the iron becomes more and more saturated, and the 
magnetic induction increases less rapidly than in direct propor- 
tion to the increase in current. It must not be considered, 
therefore, that the tractive effort between the brake shoes and 
the track is proportional to the square of the current. 



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Fig. 100. — Braking Tests of Single-Truck City Car. General Braking Data of Run P. 

When acting as generators, series motors obe}^ the laws of 
series dynamos, building up e.m.f. at a given speed, to a point 
corresponding to the resistance of the circuit. If all other 
conditions remain constant, the e.m.f. generated by a series 
machine varies directly with the speed. This e.m.f. is small 
with high resistance in the circuit, and above a certain maxi- 
mum resistance it will not "build up" beyond the e.m.f. pro- 
duced by residual magnetism. Furthermore, the readings with 
which the e.m.f. is built up depends upon the residual mag- 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 357 

netism in the field, and, as this is destroyed by vibration, the 
brakes would be expected to respond most readily immediately 
after the po^^er current had been cut off. These facts are 
brought out in the diagrams and tables. 

The general average results of the test, as shown in the synop- 
sis. Table LIII, permit a comparison with the results of similar 
tests. As these averages were complied from an extensive series 



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Fig, 101.— Braking Tests of Single-Trucli City Car. General Braking Data of Run Q. 

of runs covering twenty-five different methods of handling the 
brake, they may be taken as a representative of average condi- 
tions. Further, while the tests were made upon a particular 
type of car operating upon a level, tangent track, the results may 
be used in the consideration of other cases of magnetic brake 
application. The speed of the car at the time of the applica- 
tion of the brakes is an average maximum speed for city condi- 
tions. In the double-truck city car tests, the maximum speed 
W^s slightly below this valu^. 



358 



ELECTRIC RAILWAY TEST COMMISSION 



The average deceleration produced was more than 2.5 miles 
per hour per second, a value considerably above the average 
results of tests made on the interurban car with an air pressure 
in the brake cylinder of 40 lbs. per square inch. The detailed 
tests on the double-truck city car showed that in regular city 



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Seconds 0123 4567 

Fig. 102. — Braking Tests of Single-Truck City Car. General Braking Data Run T. 

service, the brake cylinder pressure was about 20 lbs. per square 
inch, with 45 lbs. in the storage reservoir. These facts lead 
to the conclusion that the average results of the tests covered 
in the present chapter, show a deceleration more rapid than 
is ordinarily produced by the air brake in regular city service. 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 359 

This inforniation in itself would not be sufficient, as the com- 
fort of the passengers is also an element of prime importance. 
As a matter of fact, even the most rapid stop made during the 
tests was smooth and uniform, although deceleration was some- 
what greater than would conduce to the comfort of the pas- 
sengers. 

It was found impracticable to calculate from the curves an 
exact value of the maximum deceleration. Instead of this 
the deceleration for the last second was calculated, and the 
results show this to be somewhat more than 50 per cent in ex- 
cess of the average value. This increases toward the end of 
the braking period, and is due to the increase in friction between 
the brake shoes and wheels. This increase in friction is ap- 
parently offset to a considerable extent by the increase in the 
braking current. In other words, after the brakes have once 
been set, they grip the wheels firmly, and with an imdiminished 
pressure, practically until the car comes to rest, provided it is 
on a level track. The brake shoes are, of course, released when 
the current ceases, but the diagrams show clearly that the cur- 
rent disappears only at a very low speed. As far as the results 
show, the stop is similar to that made by the air brake, with the 
possible exception of a slightly lower ratio of maximum to aver- 
age deceleration. 

The total braking force acting on the car and the braking 
force per ton are considerably in excess of the average of these 
values in the tests upon the interurban car. The value of 234 
lbs. per ton corresponds to an average cylinder pressure of at 
least 40 lbs. per square inch in the interurban tests already 
referred to. The effect of this large braking force is clearly 
seen in the short time interval (7.113 seconds) during which 
the average stop was made, and the average distance (114.7 
ft.) covered during the period. 

The general form of the braking curve is indicated by the 
ratio of the maximum to the average speed during the braking 
period. If the deceleration were absolutely uniform from the 
point of application of the brakes to the stop, the average would 



360 ELECTRIC RAILWAY TEST COMMISSION 

be just one-half of the maximum. As a matter of fact, it is 
considerably larger than this value, indicating that the speed 
did not begin to drop off immediately after the brakes were 
applied. This is readily seen from an inspection of the dia- 
grams. It is to be noticed that, in the use of this particular 
type of brake, the deceleration begins somewhat slowly and in- 
creases to a steady value within a few seconds. It holds this 
value until within one second of the stop, when it increases 
slightly, as shown above. The rapidity with which the brakes 
operate depends very largely upon the manner of handling the 
controller on the braking notches. 

The data given in the synopsis showing the average of the 
maximum values of the current during braking, is an indication 
of the back torque produced in the motors. The average time 
elapsing before this maximum value is reached shows the quick- 
ness with which the motors assume their duty as generators. 
This item is also effected to a considerable extent by the manner 
of handling the controller. The average current gives no indi- 
cation of the heating effect upon the motors, as this is propor- 
tionate at all times to the square of the current. For this 
reason the square root of the mean square current was calcu- 
lated, as this is the true measure of the heat produced in the 
motors by the braking. The service tests considered in Chapter 
II, with and without the magnetic brake, show that the heat- 
ing effect upon the motors, due to the magnetic brakes, is neg- 
ligible in the equipment under test. The ratio of the square 
root of the mean square current to the average current, com- 
monly known as the form factor, shows the effect of the shpvpe 
of the braking curve upon the heating. 

Measurements of the e.m.f. have an important bearing upon 
the results of the tests in that they show that the average 
maximum pressure was considerably below the normal working 
pressures of the motors when in regular service. The core losses 
were, therefore, small, and no injurious sparking occurred at 
the brushes on account of the braking current. 

As a final summation of the entire results of the tests, the last 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 361 

item in the synopsis is important. This shows the ampere- 
seconds required to produce a deceleration of one mile per 
hour per second, the value being 372 ampere-seconds. From 
this value the ampere-seconds required to produce greater or 
less deceleration can be calculated. Tables LIV and LV con- 
tain the general data of all of the runs and contain considerable 
information of interest. These tables show a range of duration 
of the braking period from 8.6 seconds to 6.2 seconds. This 
seems a small range, when considered in the light of the great 
variety of methods employed in applying the brakes. Sim- 
ilarly, the braking distances vary from a maximum of 164.4 ft. 
to a minimum of 90 ft. After allowing for the differences in 
maximum speed in the various tests, it is evident that the 
magnetic brake produces a stop which is remarkably uniform 
for duration and distance. The average deceleration during the 
braking period is remarkably uniform in its value, departing 
only a few per cent from the average value in any instance, 
and having a total range of between 3.10 and 2.16 miles per 
hour per second, with an average value of 2.57 miles per hour 
per second. This emphasizes the facts already stated. It is 
unnecessary here to point out the causes of the variations which 
are shown by these tables. A comparison of the results of any 
one run with the schedule makes the cause of these variations 
perfectly clear. For example, in run K a large average decel- 
eration is noted, with a corresponding very quick stop. The 
schedule shows the method of operating the brake in this case. 
An excessive current was not used at the start, but the current 
was increased to a maximum in about three seconds, and then 
gradually reduced, giving a current curve somewhat like that 
shown in Fig. 98. This is evidently an effective way of handling 
the brake. 

As an example of an extreme case in the other direction, 
run P may be cited. This is illustrated in Fig. 100. From 
this diagram it will be noted that the current was built up very 
slowly at the start, due to the car drifting a considerable dis- 
tance between the time of shutting off the power and that of 



362 ELECTRIC RAILWAY TEST COMMISSION 

the application of the brakes. During this interval the field 

magnetism in the motors was reduced by the vibration, and 

considerable time was necessary to enable the machines "to 

build" again after being short-circuited through the brake 

shoes. 

The Graphical Results. 

A study of the curves shown in Figs. 98 to 102, inclusive, 
brings out some very interesting results. The curves show the 
current, e.m.f., speed, deceleration, and distance data during 
the braking period, and are plotted on a time base. It is to 
be noted in this connection that while the time involved in the 
braking period varied considerably in the different tests, it was 
between six and nine seconds in all cases. 

The Current Curves. — The current shows a general ten- 
dency to increase rather slowly at the start, with an abrupt 
increase to a maximum value after the motors begin to generate 
e.m.f. As the brakes operate and the car decelerates, the 
current falls off, decreasing to a zero value when the car comes 
to a standstill. Fig. 98 shows a very low maximum current, 
but one which is fairly uniform throughout the entire braking 
period. Fig. 99 shows a condition where the current rises 
abruptly to an excessive maximum value. This maximum is 
335 amperes, while the average value of the current is only 
162 amperes, or less than half of the maximum. The abrupt 
rise of current in this case was due to the fact that the controller 
was turned to the 7th notch immediately after the power was 
cut off. The residual magnetism in the motors was high, and 
the resistance in the braking circuit was low, resulting in a 
rapid building up of the e.m.f. The result was a very quick 
stop. Fig. 100 shows a very small current during the first 
three seconds of the braking period. However, as soon as the 
current began to increase, it rose abruptly to its maximum 
value and remained at a high value for several seconds before 
it finally began to decrease. In this test the car drifted 200 ft. 
before the brakes were applied. The controller was first turned 
to the third braking notch and then advanced at the rate of 






BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 363 

one notch per second, producing a very slow stop. Fig. 101 
shows a braking current which is intermediate between that of 
99 and 100. It comes on more rapidly than that in Fig. 99, but 
rises somewhat higher than in Fig. 100. This results from the 
method of applying the brake. AVhile the drifting distance 
was the same in Figs. 100 and 101, the braking was done at a 
more rapid rate in Fig. 101, with the result that the time inter- 
val of the braking period was decreased. Fig. 102 shows a 
current curve which is more nearly like that of Fig. 98, in that 
the maximum value is not so large in proportion to the average 
value of the current. However, the current is considerably 
greater than that of Fig. 98 and the braking effect is not as 
good in proportion, although the time interval of the braking 
period is slightly less than that of Fig. 98. 

The Peessure Curves. — In general, the pressure curves 
have the same general form as the current curves in the various 
runs. It is to be noted that where the current is slow in rising, 
this sluggish action is due to the fact that the motors have 
not "built up" their e.m.f. rapidly. This is especially notice- 
able in Fig. 100, where the car drifted 200 ft. before the brakes 
were applied. Where the controller was turned on gradually 
during the interval of braking, it will be seen that, in general 
the maximum value of the e.m.f. occurs just previous to the 
point of maximum current. Another point of interest in con- 
nection with the pressure curves is that the maximum pressure 
did not rise above 500 volts, and, in general, varies between 
300 and 450 volts. The average maximum e.m.f. for the 
25 tests was but 345 volts, while the average value of the pres- 
sure throughout the entire period of braking was 155 volts. 

The Speed Curves. — The speed curves have the same 
general form in all of the tests which have been graphically 
represented. The speed falls off gradually at first, then at a 
more rapid rate, which remains nearly constant during the 
greater portion of the braking interval. During the first second, 
however, a still more rapid decrease in the speed occurs, due 
probably to the increased frictional effect as the speed is de- 



364 ELECTRIC RAILWAY TEST COMMISSION 

creased. It will be noted that Fig. 100 shows a very slight 
decrease in speed over the first three seconds of the braking 
interval, while the speed falls off abruptly during the remain- 
ing time. This corresponds with the slow "building up" of 
the current in the braking circuit, as brought out in the dis- 
cussion of the current curves. The other extreme is found in 
the speed curve of Fig. 99, where the speed falls off abruptly, 
almost from the start of the braking period. This is due to 
the fact that the current almost immediately rises to its max- 
imum value, a fact which was brought out in the discussion of 
the current curves. The other speed curves show character- 
istics which are between these extreme conditions. It will be 
noticed in this connection that the speed at the instant the 
brakes were applied did not vary greatly in the different tests, 
being between 17 and 19 miles per hour. 

The Deceleration Curves. — While the deceleration curves 
have the same general characteristics for all tests, it will be 
seen that they, too, are considerably affected by the general 
conditions of braking. The most rapid rise at the beginning 
of the deceleration curve is noted in Fig. 99, while the most 
gradual increase in deceleration at the beginning of the braking 
period occurs in Fig. 100. These conditions are due to the 
rapid building up of the current in Fig. 99 and to the sluggish 
action of the motors in Fig. 100. A matter of interest in this 
connection is the fact that, while the brakes did not take hold 
during the first three seconds in Fig. 100, with a consequent 
low value of deceleration during this interval of time, the 
deceleration during the remaining portion of the braking inter- 
val is greater than that obtained in Fig. 99. That is, while 
the brakes did not take hold for several seconds after the brake 
was applied in Fig. 100, when the current did build up, it at- 
tained a higher average value throughout the remaining portion 
of the braking period, than was attained in Fig. 99. The 
deceleration curves of the other tests represent graphically 
values which lie between the extreme cases just considered. 

It is to be observed that the deceleration is zero at the be- 



BRAKING TESTS ON A SINGLE-TRUCK CITY CAR 365 

ginning of the braking period in Figs. 98 and 99, while it has a 
value between 0.20 and 0.25 of a mile per hour per second in 
Figs. 100, 101, and 102. 

In the test shown by Fig. 98, the brake was applied imme- 
diately upon shutting off the power, when the car was running 
at a constant speed. In the run shown in Fig. 99 the power 
was turned on and immediately off just before the brakes were 
apphed, the result being a practically imiform speed at the 
beginning of the braking period. In both of these tests, there- 
fore, the deceleration is zero at the instant the brakes are 
applied. 

In the tests shown by Figs. 100, 101, and 102, the car drifted 
a distance of 200 ft. in each case before the brake was applied. 
In these three tests the car had begun to decelerate before the 
application of the brakes. This deceleration was comparatively 
slight, and was found to be approximately 0.23 of a mile per 
hour per second in all three tests. 

The Distance Curves. — While the distance curves have 
the same general shape in all the tests considered, it will be 
seen that the distance traversed varies considerably in the 
several tests. As would be expected, the shortest distance 
traversed during the braking period occurs in Fig. 99, where 
the deceleration is most rapid, due to the abrupt rise of the 
braking current upon the application of the brakes. The dis- 
tance was only 93 ft. The greatest distance traversed was 
164 ft., which occurs in Fig. 100. This would be expected, as 
the car ran with a sUghtly diminishing speed during. the first 
three seconds of the braking period. After the brakes began 
to act, however, the distance curve rose much more gradually. 
The distance curves shown in the other three tests graphically 
represented, have the same general characteristics as those of 
the two tests already discussed. Where the speed curve falls 
off but slightly at the start, it will be noticed that the distance 
curve rises most abruptly. In all cases the maximum slope of 
the distance curve occurs at the start, and it becomes parallel 
to the base at the point of stop. 



366 ELECTRIC RAILWAY TEST COMMISSION 

General Deductions. — A general study of the graphical 
results shows a most interesting interrelation between the curves 
for a given test. Where the current rises abruptly at the 
beginning of the braking period, it will be found that the e.m.f. 
also rises suddenly; whereas, if the current is slow in increasing, 
this is due to a sluggishness in the action of the motors as 
shown by the e.m.f. curve. It will be found that, in general, 
the current rises rapidly to a maximum value as soon as the 
motors begin to "build up," but that the time at which this 
action occurs depends largely upon the manner in which the 
braking is performed. The current increases most rapidly at 
the start when the brake is applied immediately after the 
power is turned off. On the other hand, the brakes are most 
sluggish in their action when the car has been permitted to 
drift with the power off for a considerable distance, before the 
brakes are applied. In this connection it is interesting to note 
that good braking results may be obtained even after a con- 
siderable period of drifting, if the power is turned on and in- 
stantly off before applying the brakes. This operation charges 
the fields of the motors and restores the residual magnetism, 
which may otherwise be considerably decreased, due to the vi- 
bration of the motors. This condition of affairs is brought 
out very clearly in Fig. 98. In this case the car drifted for a 
distance of 90 ft., after which the power was turned on and 
instantly off, before applying the brake. The result was that 
both the e.m.f. and current curves increased to a fair value 
immediately upon the application of the brake. The speed and 
deceleration curves show that the brakes acted very promptly 
after the controller was turned to the braking position, while 
the distance curve shows that the stop was made in a distance 
of 133 ft. This was a good average stop, as the speed at the 
beginning of the braking period was between 19 and 20 miles 
an hour. 



PART V. 

TESTS OF A STOKAGE BATTERY 
INDUSTEIAL LOCOMOTIVE. 



367 



CHAPTER XI. 

TESTS OF A STORAGE BATTERY INDUSTRIAL 

LOCOMOTIVE. 



Objects of the Tests. 

The tests were made in order to determine the relation be- 
tween the horizontal tractive effort produced by an industrial 
locomotive, and the current drawn by the motors, and also to 
find the general efficiency of the equipment when hauling loads 
under normal conditions of speed. The condition of the track, 
as affecting the results, was also carefully investigated. 



Synopsis of Results. 

The general results of the tests are shown in the synopsis 
given in Table LVI. 

Table LVI. — Synopsis of Results. Industrial Locomotive Tests. 
Part I. Locomotive Pulling Against Fixed Anchor. 



Run number 

Kind of track 

Controller notch num- 
ber 

Maximum horizontal 
effort, lbs 

Maximum current, 
amperes 

Horizontal effort per 
ampere, lbs 



1 

Straight 


2 
Curved 


3 

Straight 


4 
Curved 


5 

Straight 


1 


1 


2 


2 


3 


2400 


2080 


3500 


3400 


1680 


80 


80 


110 


120 


120 


30.0 


26.0 


31.8 


28.3 


14.0 



6 
Curved 

3 

1160 
130 

8.9 



In runs 1, 2, 5, and 6 the horizontal effort was limited by the limit of dis- 
charge rate of the batteries, while in runs 3 and 4 the limit was set by the 
slipping of the wheels. These runs cover the best conditions of track. 

369 



370 



ELECTRIC RAILWAY TEST COMMISSION 



Part II. Locomotive Running Without Trailers. 



Run number 

Kind of track 

Condition of track . . . 

Controller notch num- 
ber ' 

Speed, miles per hour 

Electromotive force, 
volts 

Current, amperes . . . . 

Power, watts 



7 

Straight 

Dry 


8 

Curved 

Dry 


9 

Straight 

Dry 


10 

Curved 

Dry 


11 

Straight 
Dry 


1 
0.70 


1 
0.51 


2 
1.44 


2 
1.20 


3 

2.61 


48.7 

13.5 

660 


48.4 
21.6 
1047 


95.8 
14.6 
1397 


94.7 
23.4 
2213 


92.6 
33.9 
3133 



12 

Curved 

Dry 

3 
2.29 

89.6 
48.1 
4301 



Part III. Locomotive Hauling Trailers. 



Run number 

Kind of track 

Condition of track . . . 

Controller notch num- 
ber 

Speed, miles per hour 

Horizontal effort, lbs. 

Electromotive force, 
volts 

Power, watts 



13 

Straight 
Dry 


14 

Curved 

Dry 


1 

.68 
116 


1 
.48 
183 


48.3 
656 


48.0 
975 


19 

Straight 

Dry 


20 

Curved 

Dry 


3 

2.61 

95 


3 

2.33 

217 


95.2 
3312 


91.2 
4090 



15 

Curved 

Oily 


16 

Straight 

Dry 


17 

Curved 

Dry 


1 
.5 
164 


2 

1.36 

113 


2 

1.21 

195 


48.0 
820 


94.8 
1460 


95.7 
1915 



18 
Curved 

Oily 

2 

1.30 

194 

95.7 
1770 



Run number 

Kind of track 

Condition of track . . . 

Controller notch num- 
ber '. . . . . 

Speed, miles per hour 

Horizontal effort, lbs. 

Electromotive force, 
volts 

Power, watts 



21 

Curved 

Oily 

3 

2.49 

172 

91.3 
4025 



Load consisted of two light trail cars, weighing with load 6300 lbs. 
Since two cars and locomotive could not be accommodated on a curve at 
the same time, the pull was read with the two cars on the curve. 

General Conditions of the Tests. 
The tests were conducted in the court of the Palace of Elec- 
tricity on a special track installed for the purpose of operating 
this locomotive. Fig. 103 shows the general arrangement of 
this track, with the dimensions of the various curves and straight 
portions. The track gage was 21.5 inches, and the total length 
was 663 ft. All curves were laid out with a radius of 12 ft. to 



iSTOUAGE BATTERY INDUSTRIAL LOCOMOTIVE 371 

the track center, and the track was arranged to show the per- 
formance of the locomotive under severe conditions of opera- 
tion. The rails and ties were of the well-kno\vn standard 
construction of the C. W. Himt Company, the ties being spaced 
2 ft. between centers. 




Fig. 103. — General Arrangement of Track. Industrial Locomotive. 

The locomotive was designed and built by the C. W. Hunt 
Company, for industrial use in the hauling of cars loaded with 
very heavy materials in shops and yards, where simplicity and 
cheapness of maintenance are primary considerations, and speed 
is of minor importance. The total weight of the locomotive was 



S72 ELECTRIC RAILWAY TEST COMMISSION 

approximately 5 tons and it was designed to haul loads up to a 
maximum of 5 tons, at speeds varying between 0.5 and 2.5 miles 
per hour on straight and level track, with a 25 per cent reduction 
on curves. 

THE LOCOMOTIVE EQUIPMENT. 

The locomotive was so designed that the driving motors, with 
their speed reducing gear cases, were located above the platform 
carried on the trucks, suitable supports being provided for this 
purpose. Two trucks were pivoted on the body of the locomo- 
tive in such a way as to enable it to easily pass curves of a 12 ft. 
radius. The wheels were provided with outside flanges and 
in turning curves the outer wheels ran on flanges, over a spe- 
cially constructed rail. The increased circumference compen- 
sated for the difference in length of the two rails of the curves, 
and slipping and friction were greatly reduced. As the uses 
to which these locomotives are put require a large horizontal 
effort on curves, the desirability of this feature is evident. 

The motive power was supplied by two series motors with a 
rated capacity of two horse power each, and designed for a normal 
e.m.f. of 75 volts. The motors were four-pole, and the arma- 
tures were of the two-circuit or series type. 

The motors were covered by dust and water-proof cylindrical 
cases. The power was transmitted to the axles through a reduc- 
tion gear and a chain drive. The reduction gear consisted of a 
train of gear wheels conveniently arranged for inclosure in a 
cylindrical oil-tight case. By means of an intermediate pinion 
the driving chain was carried over spur gears on both driving 
axles, thus giving a large tractive effort. The reduction ratio 
from the motor axles to the car wheels is 20.65 to 1. 

A small controller was arranged so that it could be operated 
from either end of the platform. There were four controller 
positions, the first being the charging point on which all cells 
of the storage battery were connected in series directly to the 
charging leads and with the motors cut out. In the second 
position the motors were thrown in series, the two sets of the 
storage battery being in parallel. In the third position both the 




STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 373 

battery sets were in series. In the final position of the con- 
troller the battery sets were in series, the motors being connected 
in parallel. Fig. 104 shows the connections corresponding to 
the several controller positions. A reverse switch permitted 
the same set of connections to be made with the car going in 



HH' 

1 — 

! 

|-C3— o 1|^| '—"^: 1 

I r-,^ _ I u , Storage Charging Position 



pi 1 Controller Notch 




No.l 



Controller Notcli 
No 2 



Controller Notch 
No. 3 



S Switch 1 Motor No. 1 

A Ammeter 2 Motor No. 2 

' V Voltmeter 

Fig. 104. — Diagram of Connections Industrial Locomotives. 



either direction. An ammeter and voltmeter, placed in a case 
near the controller, were of use in charging the cells and in fur- 
nishing a general indication of the load upon the locomotive. 

Upon the central part of the locomotive platform was carried 
a storage battery consisting of 48 chloride accumulator cells 



374 ELECTRIC RAILWAY TEST COMMISSION 

manufactured by the Electric Storage Battery Company. 
These cells were arranged in two groups of 24 each, which groups 
could be arranged in series or in parallel. The following data 
relate to these cells: 

Type E-9 

E.m.f. per cell, when charging with 20 amperes, volts 2. 16 

E.m.f. per cell on open circuit, volts 2.08 

Capacity, in amperes when discharged in 8 hours 160 

Number of positive grids per cell 4 

Number of negative grids per cell 5 

Weight per cell with acid, pounds 52 

Total weight of battery, pounds 2500 

Weight of acid per cell, pounds 101 . 5 



General Description of the Tests. 

The tests comprised two general classes: (a), those made with 
the locomotive pulling against a fixed anchor; and (b) those in 
which the locomotive operated upon the track under normal 
conditions of speed. 

In order that the tests might be comprehensive and systema- 
tic, they were carried out in accordance with the following 
schedule : 

Series A. Locomotive pulling against an anchor; straight 
track, rusty, wet, and muddy. 

Series B. Locomotive pulling against anchor; straight track, 
rusty, and dry. 

Series C. Locomotive pulling against anchor; curved track, 
clean, dry, and rusty. 

Series D. Locomotive pulling against anchor, curved track, 
muddy, and rusty. 

Series E. Tests of starting currents. for various conditions. 

running light on controller notch 

running light on controller notch 

running light on controller notch 

hauling trailers loaded with 6300 
lbs. and operating on controller notch No. 1. 



Series F. 
No. 1. 
Series G. 


Locomotive 


Locomotive 


No. 2. 




Series H. 


Locomotive 


No. 3. 




Series I. 


Locomotive 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 375 

Series J. Locomotive hauling trailers loaded with 6300 
lbs. and operating on controller notch No. 2. 

Series K. Locomotive hauling trailers loaded with 6300 
lbs. and operating on controller notch No. 3. 

From the results of these tests the data for the runs made 
on the different controller notches were arranged so as to per- 
mit of convenient comparison as follows: 

Part 1. — Locomotive Pulling Against Anchor. 

Run 1. Straight track, notch No. 1. 
Run 2. Curved track, notch No. 1. 
Run 3. Straight track, notch No. 2. 
Run 4. Curved track, notch No. 2. 
Run 5. Straight track, notch No. 3. 
Run 6. Curved track, notch No. 3. 

Part 2. — Locomotive Running Without Trailers, 

Run 7. Straight track, notch No. 1. 
Run 8. Curved track, notch No. 1. 
Run 9. Straight track, notch No. 2. 
Run 10. Curved track, notch No. 2. 
Run 11. Straight track, notch No. 3. 
Run 12. Curved track, notch No. 3. 

Part 3. — - Locomotive Hauling Trailers. 

Run 13. Straight, dry track, notch No. 1. 

Run 14. Curved, dry track, notch No. 1. 

Run 15. Curved, oily track, notch No. 1. 

Run 16. Straight, dry track, notch No. 2. 

Run 17. Curved, dry track, notch No. 2. 

Run 18. Curved, oily track, notch No. 2. 

Run 19. Straight, dry track, notch No. 3. 

Run 20. Curved, dry track, notch No. 3. 

Run 21. Curved, oily track, notch No. 3. 



376 



ELECTRIC RAILWAY TEST COMMISSION 



ORIGINAL MEASUREMENTS. 

Measurements of Horizontal Effort. 

In the horizontal effort tests, the locomotive pulled against a 
Stormbaugh guy anchor screwed in the ground to the eye and 
at a sharp angle with its surface. A stranded guy wire served 
to connect the anchor with the draw-bar of the locomotive. 

In the trailer hauling tests, it was found to be impracticable 
to secure sufficient loading to reach the capacity of the loco- 
motive, partly because there were not enough trailers available 
to carry such a load, and partly because conditions at the Fair 




I Wood ^•r-^i—\^ ~ff] 



^_ r < < < ^ 



ittr 



Locomotive Platform 



O 



To Anclior 

>- 



Fig. 105. — Oil Dynamometer. Industrial Locomotive. 

Grounds did not permit of securing 50 tons of compact material 
at the time of the tests. It was not considered necessary, how- 
ever, to so load the locomotive, because the static tests gave 
all of the necessary data for determining the general relation of 
current and horizontal effort, and a sufficient load was hauled 
to show the relation between the speed when hauling no trailers 
and the speed when hauling a reasonable load. 

For the purpose of measuring the horizontal effort, a special 
oil dynamometer was constructed as shown in Fig. 105. An 
eight-inch Christensen air-brake cylinder. A, was mounted on a 
two-inch plank, which was arranged to rotate on a cast-iron 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 377 

pin, P, securely fastened to the car platform. A flat steel lever 
7?, with its fulcrum at M, transmitted the resisting force from 
the anchor cable to the piston rod. In order to reduce the 
internal friction of the cylinder, the packing rings of the piston 
were removed. The space behind the piston was filled with oil 
and a pressure gage was connected to this oil chamber for the 
purpose of reading the pressure produced on the oil by the 
piston. The oil lost by leakage was replaced by pumping 
additional oil behind the piston from time to time. The total 
ratio of the lever system was so arranged that the push upon 
the piston was 1.855 times that at the draw-bar. The area of 
the piston was 50.27 sq. in., so that for every one thousand 
pounds horizontal effort the pressure registered by the gage was 
36.9 lbs. per square inch. In the actual operation of this 
apparatus, it was found necessary to clamp the dynamometer 
platform to the car platform when a large horizontal effort was 
to be measured, as there was a considerable tilting effect. The 
dynamometer was first allowed to take its natural position and 
it was then clamped securely in this position. When hauling 
the trailers this was not found to be necessary and the dynamo- 
meter was allowed to rotate about the pin P. 

Electrical Measurements. 

As the larger part of the tests comprised a study of the static 
pull of the locomotive, it would have been necessary to waste 
in resistance a large amount of the energy stored in the batter- 
ies, if the full battery pressure had been used. In order to save 
battery energy the batteries were tapped at such points as to 
give the desired current without the insertion of resistances, the 
variation in the current being produced by changing the num- 
ber of cells furnishing the current. For the controller positions 
in which the batteries were normally connected in parallel, the 
separate batteries were similarly connected. While this oper- 
ation made the tests somewhat tedious, the results amply 
justified the effort made, as it was possible to make many more 
tests with one battery charge than would otherwise have been 
the case. 



L 



378 ELECTRIC RAILWAY TEST COMMISSION 

The current was allowed to attain a steady value for each 
condition of the tests, and a series of measurements of e.m.f. 
and current were then made, corresponding to the several con- 
troller notches, Weston instruments being used. No attempt 
was made to determine the efficiency of the battery, as this was 
beyond the purpose of these tests. Furthermore, the conditions 
of operation were not the same as those of the ordinary applica- 
tion of the locomotive. 

Speed Measurements. 

The speed during the tests when the locomotive was running 
light or hauling trailers, was determined by noting the time of 
passing fixed points on the track. 

WORKING UP THE RESULTS. 

The results were first corrected for inaccuracies in the instru- 
ments and the data were then assembled on summary sheets, 
one of these being prepared for each test. The calculated results 
of the tests covering the performance of the car when pulling 
against an anchor, were finally transferred to curve sheets and 
represented in graphical form. It was found impracticable to 
represent graphically the results of the tests showing the per- 
formance of the locomotive under running conditions. These 
calculations were, therefore, worked up in tabular form. 

Results of the Tests. 

The general results of the tests have already been summarized 
in the synopsis, Table LVI. As this table shows all of the prin- 
cipal results obtained, for the running tests, these data will not 
be repeated here. However, additional data concerning the 
static tests will be found graphically represented in Figs. 106 
to 111, inclusive. This series of six sets of curves shows the 
variations in the several quantities involved, such as horizontal 
effort, e.m.f., and power, with change of current. 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 379 

Discussion of Results. 

In studying the results of these tests, it should be borne in 
mind that the tests comprised two different series: the first was 



5000 50 



4000 40 



3000 30 



2000 20 



£000 10 





Amperes 

















/ 














/ 


/ 














/ 


/ 














/ 


/ 












7 

/ / 


/ 


1 










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7 


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f 


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/ 


/ 




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2400 



2000 



1600 



1200 



800 



400 



20 40 60 

Fig. 106. — General Data, Industrial Locomotive Tests. Run No. 1. 



80 



intended to show the operation of the locomotive in starting 
loads up to the limit of its capacity; while the second was for 
the purpose of obtaining information as to the performance of 



380 



ELECTRIC RAILWAY TEST COMMISSION 



the locomotive when hauling various loads. It was possible 
to carry the first series far beyond the limit of the ordinary 
demand upon the locomotive. In the second part of the tests, 
owing to the impracticability of obtaining sufficient load, it 



e s 
















/ 


5000 50 














/ 


/ 


4000 40 














/ 


/ 












I 


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3000 30 












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2000 20 










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2000 



1600 



1200 



800 



400 



Amperes 20 40 60 

Fig. 107. — General Data, Industrial Locomotive Tests. Run No. 2. 



80 



was not possible to show the performance of the locomotive 
hauling heavily loaded trailers. However, a sufficient load was 
applied to obtain useful and interesting information regarding 
the efficiency of the equipment when hauling light loads. This 
efficiency would be considerably higher when hauling heavy 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 381 

loads, and, from the data obtained from the anchor tests, some 
idea is given of the performance when hauhng heavy loads. 

Table LVI shows the general data obtained from the anchor 
tests. The table is so arranged that the results of the tests on 



7000 



6000 60 



5000 50 



4000 40 



3000 30 



3000 20 



1000 10 





















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3600 



saoo 



2800 



2400 



60 go l6o 120 
Amperes 

Fig. t08. — General Data, Industrial Locomotive Tests. Run No. 3. 

the curved track are placed alongside those obtained upon the 
straight track, for each controller position. In all cases the 
horizontal effort produced by a given current is less on the curved 
track than on the straight track. On the first notch the differ- 
ence amounts to 13.3 per cent, on the second notch to 11 per 
cent, and on the third notch to 36 per cent. It is evident that 



'382 



ELECTRIC RAILWAY TEST COMMISSION 



the locomotive pulls at a great disadvantage on a curve, even 
with the compensating flange already described. The tests 
shoW; however, that it developed a large horizontal effort, even 
on a curve, with a reasonable expenditure of current. As far 



8000 



7000 



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4000 



2000 20 



1000 10 



























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2800 



2000 



1600 



20 



60 
Amperes 



Fig. 109. — General Data, Industrial Locomotive Tests. Run No. 4. 



as the production of horizontal effort is concerned, there is no 
choice between the first notch and the second notch. The 
reason for this is that the motors are connected in series in both 
cases. On the second notch, the horizontal effort was carried 
up to a point at which the wheels slipped. Naturally, the third 
notch gave less horizontal effort against the anchor, for a given 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 383 

current, than the others, as in this position the motors were in 
parallel. As this is the high speed notch, it would not be used 
in starting the locomotive. 

The second part of Table LVI shows the performance of the 
locomotive running light at various controller notches and on 
a dry track, and on both straight and curved portions of the 
track. This test shows approximately the amount of power 
which would be consumed in the locomotive itself when hauling 
trailers, although the electrical losses would be somewhat more 



8000 30 



2000 



1000 



20 

















































y 






















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1600 



800 



40 



60 
Amperes 



100 



Fig. 110. — General Data, Industrial Locomotive Tests. Run No. 5. 



under these conditions. The effect of the increased friction on 
curves is evidenced both by the reduction in speed and by the 
increased consumption of power. On notch No. 1, the speed 
is reduced to 74 per cent; on notch No. 2, to 84 per cent; and on 
notch No. 3, to 88 per cent, of the corresponding values on 
straight track. The respective increases in power amount to 
59 per cent, 58 per cent, and 37 per cent. 

Part 3 of Table LVI gives data showing the performance of 
the locomotive when hauling a light load. A comparison of 
the data with those appearing in other parts shows that the 
effect of this load upon the speed, as well as the effect on the 



384 



ELECTRIC RAILWAY TEST COMMISSION 



power consumption, is entirely negligible. The latter will be 
greater at notches Nos. 2 and 3 on the straight track, and less 
on all notches on the curved track. The table also shows the 
horizontal effort necessary to haul the given load at various 
speeds and on different kinds of track. The friction on the 
curved track was considerably reduced by oiling. This is 
shown by the decrease in power absorbed, by the increased 
speed, and by the diminished horizontal effort necessary to haul 
the trailers. Average values of the tractive effort per ton, 
calculated from these data are 34.3 lbs. per ton for the straight 
track; 62.9 lbs. per ton for the curved track, dry; and 56.7 lbs. 
per ton for the curved track, oiled. 



3000 



> 
2000 20 



1000 10 



0^ 

Amperes 

























y 


y 
























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1200 



800 



400 



20 40 60 80 100 120 140 

Fig, 111. — General Data, Industrial Locomotive Tests. Run No. 6. 



Figs. 106 to 111, inclusive, show the general performance of 
the locomotive when pulling against an anchor. Fig. 106 shows 
that 16.5 amperes were required before any pull was observed 
upon the dynamometer. This much current was used in over- 
coming friction. The horizontal effort then increased at a uni- 
form rate to a value of 2400 lbs., beyond which it was not 
considered advisable to go, on account of the current capacity 
of the battery, although no slip was observed at this point. 
The horizontal effort was about 24 per cent of the weight of 
the locomotive at the final value of current used. 

Fig. 107, which represents the results of a test similar to that 
shown in Fig. 106 except that the locomotive was located on a 



STORAGE BATTERY INDUSTRIAL LOCOMOTIVE 385 

curve, shows that 24 amperes were required before a pull was 
registered on the dynamometer. The horizontal effort curve 
rises less imiformly than in the preceding case, and it shows a 
tendency to become more nearly tangent to the base line after 
a value of 1800 lbs. pull has been attained. The horizontal 
effort corresponding to 80 amperes in this case is 2080 lbs., 
which is 87 per cent of the value obtained in the preceding test. 

Fig. 108 shows the results of several tests w^ith the locomotive 
puUing on a straight track, and with the controller at the second 
notch. Dry, clean, rusty track permitted a horizontal effort 
of 3500 lbs. before slipping began. The wheels slipped at 3380 
lbs. when the track was wet, muddy, and rusty. The corres- 
ponding limit for wet, muddy, and smooth track was 2660 lbs. 
The current necessary to produce a reading on the dynamometer 
was 16 amperes, practically the same as in the first test dis- 
cussed. The horizontal effort rose at a very uniform rate imtil 
high values of the current were reached. This portion of the 
curve shows a less rapid increase in the horizontal effort, due 
probably to the rapid heating of the motors with the large cur- 
rent flowing. 

Fig. 109 shows the results of the companion tests on the sec- 
ond notch, but with the locomotive pulling on a ciu've. The 
starting current here was larger than that shown in Fig. 108, 
being 20 amperes. The horizontal effort curve did not rise as 
uniformly as on the straight track, and the wheels began to slip 
on a wet, muddy, and curved track at 2900 lbs.; and on a dry, 
clean, rusty track at 2400 lbs. These values are somewhat 
below those of the preceding test. As would be expected, these 
high values were reached at a correspondingly increased current, 
on account of friction introduced by the curve. 

Figs. 110 and 111 show the performance of the locomotive 
with the controller at the third notch, and on a straight and a 
curved track, respectively. As stated before, these tests were 
made simply to obtain data for comparison with other tests. 
The locomotive acted at a great disadvantage, and no conclu- 
sions as to the performance upon the third notch should be 



386 



ELECTRIC RAILWAY TEST COMMISSION 



drawn from the results of these tests. At this notch 31» am- 
peres were required to produce a reading on the straight track, 
and 25 amperes on a curved track; and in both cases the hori- 
zontal effort rose uniformly. The effect of the curvature of the 
track is clearly indicated by the fact that while 120 amperes 
produced 1680 lbs. on a straight track, the same current pro- 
duced only 1040 lbs. on a curved track. 

A general survey of the entire series of tests leads to the con- 
clusion that this locomotive has the ability to produce a large 
horizontal effort with moderate consumption of current; this 
effect being produced by the large gear ratio employed. 



1 

{ 



PART VI. 

ALTEENATING CURRENT LOSSES IN 
RAILS AND TRACK. 



387 



CHAPTER XII. 

ALTERNATING CURRENT LOSSES IN STEEL RAILS AND 
IN OTHER STEEL AND IRON SECTIONS. 



Objects of the Tests. 

The principal object of these tests was to ascertain the energy 
losses taking place in steel rails when they are under the influ- 
ence of alternating currents, and to compare these losses with 
those resulting from the rails being influenced by equivalent 
direct currents. The effects of variations in both current and 
frequency values were also observed. 

A second object of the tests was to investigate the electrical 
energy losses peculiar to rail and bar sections of various forms, 
in order that data might be accumulated to supply the basis 
of an empirical formula to express these losses. It was also 
desired to study other features during the investigations, such 
as the rise in temperature of a section under test, and the varia- 
tion in power factor with changes in current and frequency. 

Synopsis of Results. 

On account of the nature of the results of these tests, it has 
been considered impracticable to summarize the results in a 
single table. The synopsis at the beginning of the chapter is 
therefore omitted and the graphical presentation is depended 
upon to show the scope of the work. 

Conditions of the Tests. 

With the growing importance of alternating current motors 

in the practical development of the electric railway, the losses 

due to the alternating currents flowing in rails naturally demand 

attention, as it has long been recognized that the losses in 

389 



390 ELECTRIC RAILWAY TEST COMMISSION 

steel rails, due to the flow of alternating currents, are much 
larger than those which occur with direct currents. 

The work done upon this subject up to the present time, both 
experimentally and by mathematical deduction, indicates that 
the current is driven to the surface of the conductor by means 
of a counter electromotive force generated in the conductor by 
the reversal of the magnetic flux. The electromotive force 
produced by the flux is greatest at the center, diminishing to 
the periphery of the rail, where it is a minimum. The conse- 
quence is an uneven distribution of the current in the rail, with 
a consequent increase of the actual resistance met by the current 
flowing. This result is known as "skin" effect in conductors, 
the name indicating that the current is conducted along the 
surface of the conductor. This "skin" effect is not very serious 
in the case of copper conductors, but with materials having a 
high magnetic permeability the magnetic flux produced by the 
current assumes a deflecting value which causes a considerable 
increase in apparent resistance. 

In order to obtain information and data on this subject, a 
series of tests was undertaken by the Commission on single 
lengths of steel rails and on short lengths of steel of other sec- 
tions. These tests covered a range of current of from 50 to 
600 amperes per rail, and a range of frequency of from 10 to 
60 cycles per second. 

A rational mathematical expression of the loss due to the 
flow of an alternating current in a steel rail, is quite complex 
and is not of such form as to be readily used in calculation ; and, 
therefore, in the obtaining of data, useful in constructing a sim- 
ple empirical formula, tests undertaken on variously shaped 
sections, including rectangular, square, and round steel forms, 
and wrought-iron gas pipe, are most important. 

The above indoor tests were later supplemented by a series 
of outdoor tests made upon the stretch of track lying north of 
the Transportation Building at the St. Louis Exposition. This 
has been called the "Test Track," and it is the track upon 
which the tests of the single-truck car, described in earher 



ALTERNATING CURRENT LOSSES 391 

chapters, were made. Both the alternating and the direct 
current resistance tests inckide data obtained from the track 
alone, the "overhead" alone, and the combined track and 
"overhead." A complete description of the outdoor tests, 
including the results obtained, will be found in Chapter XIII, 
Part VI. 

The investigations on single-rail lengths and other steel and 
iron sections, the results of which are contained in the present 
chapter, were performed in the exhibit space of the Bullock 
Electric Manufacturing Company, Block 15 of the Palace of 
Electricity at the Louisiana Purchase Exposition, and the 
experimental work was done during the months of July, August, 
and September, 1904. 

The Bullock Electric Manufacturing Company had a large 
working exhibit, and a portion of this was most admirably 
adapted to that part of the work of the Conmiission covering 
the experimental investigations of alternating losses in rails. 
The machines used in this connection were a 500 k.w. rotary 
converter, a 250 horse-power direct current motor coupled 
directly to an alternator of 200 k.w. capacity, and a 150 horse- 
power direct current motor belted to a 150 k.w. direct current 
generator. These machines were all wired up to a large test- 
ing table, in such a manner that various combinations of ma- 
chines and circuits could be readily made. 

Power was furnished to the rotary converter from a 6600, 
three-phase, 25 cycle circuit supplied by the Exposition gen- 
erators in the Palace of Machinery. The pressure was reduced 
to 385 volts by means of three 150 k.w. oiled-cooled trans- 
formers, and then supplied to the rotary converter. The direct 
current side of the rotary converter furnished power at a pres- 
sure of 550 volts. 

The motor of the motor-generator set was designed for a 500 
volt circuit, and this machine coukl be driven directly from the 
rotary converter by making the proper connections at the test- 
ing table. The alternator of this motor-generator set was a 
three-phase 2200 volt, 60 cycle machine, 



392 ELECTRIC RAILWAY TEST COMMISSION 

The direct current motor and generator were designed for a 
220 volt circuit, and 220 volt mains were available at the test- 
ing table. The connections were so arranged that this set could 
be started on the 220 volt circuit, and, by throwing a switch, 
the generator and the 220 volt mains could be placed in series, 
producing a combined pressure of approximately 450 volts. 

The rotary converter was usually started from the direct 
current side, power being furnished by the 450 volt circuit just 
mentioned. After the machine had been brought up to speed, 
it was synchronized with the alternating current-power circuit, 
and then switched over to this circuit. 

It is seen from the above description of the equipment and 
of the circuits available in this exhibit, that an opportunity was 
presented for doing a large amount of experimental work in- 
volving wide ranges of current and frequency. A 50 k.w., 
6600 to 110 volt transformer of the General Electric Company 
make, was loaned to the Commission by the Mechanical and 
Electrical Department of the Louisiana Purchase Exposition. 
With the addition of the necessary instruments and auxiliary 
devices, this completed the equipment used in the experimental 
determination of the alternating current losses in rails and track, 
which are discussed in this chapter, and in Chapter XIII. 

General Description of the Tests. 

Tests were made upon two single-rail lengths of different 
cross-sectional areas. These rails were tested one at a time, 
the three-voltmeter method of making power measurements 
being employed. In addition, a series of similar investigations 
was carried out on steel bars of variously shaped sections, and 
of different cross-sectional areas. Tests were also conducted 
upon a wrought-iron gas pipe. 

The tests were made at frequencies of 10, 15, 20, 25, 30, 40, 
50, and 60 cycles per second. For each frequency, measure- 
ments were made at currents of approximately 50, 100, 200, 300, 
400, 500, and 600 amperes. Both electrical and temperature 
measurements were taken for all conditions. 



ALTERNATING CURRENT LOSSES 393 

Seven separate series of tests were made in all. Of these, 
two were made on standard rail sections, four were conducted 
on various steel sections of different lengths and cross-sectional 
areas, and one was made upon a wrought-iron gas pipe. Con- 
siderable attention was paid to the investigations relating to 
the two standard rail sections, the tests covering the other five 
sections occupying but a comparatively short interval of time. 

The preliminary work preparatory to the investigations con- 
tained in the present chapter occupied a considerable period 
of time, as it was necessary to construct special apparatus and 
to perform many preliminary experiments. It also took some 
time to obtain suitable rail sections and to prepare the proper 
terminal connections for the same. The question of suitable 
terminal connections was a serious one at first, but it was 
finally decided to use tapered brass plugs, of approximately 
H in. in cross-sectional area, which were driven through tapered 
holes near the ends of the section to be tested. Holes were 
bored in these plugs for the purpose of joining them to the 
cable connections, which was done by means of soldered joints. 
This means of connecting to the section under test was found 
to be very satisfactory, no undue heating at the joints being 
observed. In all cases the length of the test specimen between 
the centers of the terminal plugs was accurately determined, 
and this length was used in the final calculations. Measure- 
ments were made of resistances and losses when using the direct 
currents, in addition to the tests made with alternating cur- 
rents. The various tests have been arranged for convenience in 
order as follows: 

Test No. 38. — The tests were made on a steel Tee-rail 
section with a cross-sectional area of 5.7 sq. in. and a weight 
of 56 lbs. per yard. The section was A. S. C. E. standard, and 
the length tested was 26.07 ft. 

Test No. 39. — This series comprised tests on a steel rail 
of Tee-shape with an area of 7.84 sq. in., and a weight per yard 
of 80 lbs. The section was the A. S. C. E. standard and the 
length tested was 27.83 ft. 



394 ELECTRIC RAILWAY TEST COMMISSION 

Test No. 40. — This series was made upon a square steel 
section having an area of 6.29 sq. in., and a weight per yard of 
64.15 lbs. The length tested was 8.56 ft. 

Test No. 41. — This series comprised tests on a round sec- 
tion having a diameter of 3 in. and an area of 7.1 sq. in. 
The weight per yard was 72 lbs. and the length tested was 
8.16 ft. 

Test No. 42. — This test was on a round steel section, having 
a diameter of 2.5 in. and an area of 4.97 sq. in. The weight 
per yard was 50.6 lbs. and the length tested was 7.63 ft. 

Test No. 43. — This comprised tests on a piece of tool steel 
having a square cross-section with a diameter of 2.02 in., and 
an area of 4.05 sq. in. The weight per yard was 41.3 lbs. and 
the length tested was 6.95 ft. 

Test No. 44. — This comprised tests on a wrought-iron gas 
pipe, having an inside diameter of 3.07 in., and an outside 
diameter of 3.51 in. The cross-sectional area of the iron was 
2.27 sq. in., the weight per yard 22.72 lbs., and the length 
tested, 18.43 ft. 

It will be seen from the above description of the various 
tests, that the lengths of the different steel sections were not 
nearly as great as those of the rails tested. It was found 
impracticable to obtain either greater lengths or larger sections, 
at the time the tests were made. 

ORIGINAL MEASUREMENTS. 

In making the tests at frequencies of 60, 50, and 40 cycles 
per second, the electrical connections were at first as shown in 
Fig. 112. The rotary converter supplied power to the motor 
side of the motor-generator set and the frequency of the gen- 
erator was adjusted by varying the speed of this motor by 
means of its field rheostat. The alternating current was taken 
from the generator side of the motor-generator set, connection 
being made to the high pressure winding of the General Electric 
transformer through an oil switch. The low pressure side of 
this transformer was short-circuited directly through the rail 



ALTERNATING CURRENT LOSSES 



395 



under test in series, with an ammeter shunt and the non- 
inductive resistance described below. 

Later it was found unnecessary to run the rotary converter 
on all tests at the higher frequencies, as the direct current mains 
and the direct current motor-generator set could be used to 
advantage in this connection, as shown in Fig. 113. Here the 
250 volt power circuit was placed in series with the armature 
of the 250 volt generator, and power was supplied to the motor- 



IDransfoTmer 




Fig. 112. — Diagram of Connections for A. C. Tests. 

generator set at 500 volts. In other respects the connections 
were the same as in Fig. 112. 

In the tests where the frequencies were 30, 25, 20, 15, and 10 
cycles per second, the armature of the driving motor was sup- 
plied with power from the 250 volt direct current generator, 
while the field of this machine was excited from a circuit in 
which the pressure was obtained from the 250 volt power 
mains and the driving generator connected in series. By this 
arrangement the driving motor was given a strong magnetic 
field and the pressure across the armature could be reduced to 
a low value, with a resultant decrease in speed. The con- 
nections were the sanie as those in Fig. 113, except that the 



396 



ELECTRIC RAILWAY TEST COMMISSION 



armature of the 500 volt motor was connected directly across 
the brushes of the 250 volt generator. 

By proceeding in the manner described above, it was pos- 
sible to obtain any frequency desired, ranging from 60 to 10 
cycles per second. The alternating current generator was run 
at normal speed when a frequency of 60 cycles per second was 
desired, and the speed was reduced to one-sixth of the normal 
value when the 10 cycle tests were made. 

Methods Employed in Making Electrical Measurements. 
Considerable time and -thought were put into the selection of 
the most desirable method to be employed in making the elec- 
trical measurements involved in these investigations. 




Fig. 113. — Diagram of Connections for A. 0. Tests. 

Current Measurements. — The measurements of current 
were readily obtained by means of a "hot-wire" ammeter of 
the Hartmann and Br aim type. The instrument employed was 
supplied with two shunts, one for a maximum scale reading 
of 600 amperes and the other for a maximum scale reading of 
200 amperes. Both of these shunts were used, no current 
values below 300 amperes being measured, with the 600 ampere 
shunt. 



ALTERNATING CURRENT LOSSES 



397 



Pressure Measurements. — The problem of measuring the 
pressures was not as easy of solution as that of measuring the 
currents. While the currents involved were large, the pres- 
sures were very small, being in many cases considerably less 
than one volt. When direct current measurements were made, 
the solution was simple, as accurate Weston instruments de- 
signed for readings at low pressures were used. On the other, 
hand, the alternating current measurements were the most 
important, and yet no accurate alternating current instru- 
ment for the low pressure was available, the best instrument 
obtaiaable being a standard Weston alternating current volt- 



(Q) 



Primaries 
to Multiple 
—120 V. 



CE 



^ 



Primaries 
to Series Multiple. 

-240 Vr 



nzzoniD 

i n c n 











N.P. 











n n n n 






© 



SecondarieB 
in Multiple. 




Primaries 
to Series. 
480 V.- 



|t 480 V.— >j 

kw 



,w,v ® 



r^ 



60 V-: i 

Secondaries 
in Series Multiple 



'^^^. 



— 120 V:— ^ 

Secondaries 

to Series. 



Fig. 114. — Pressure Transformers Connections for A. C. Tests. 



meter with a full scale deflection of 7J volts. As this instru- 
ment would not give accurate readings of the low pressures 
involved, it was necessary to use a "step-up" pressure trans- 
former, and one made by the General Electric Company was 
accordingly used. It had four primary and four secondary 
coils, the different connection combinations of which are shown 
in Fig. 114. Ratios of transformation of one to one, one to two, 
one to four, one to eight, and one to sixteen were obtainable 
from this transformer. All of these combinations were used at 
various stages of the tests. 

Power Measurements. — Great difficulty was encountered 
in finding a satisfactory method of conducting the measure- 



398 



ELECTRIC RAILWAY TEST COMMISSION 



ments of the amount of power absorbed in the rail with an 
alternating current flowing. All standard wattmeters are 
wound for a pressure of 110 volts or more, whereas the pres- 
sures involved in these measurements were in many cases less 
than one volt. There was little time for experimentation in 



I 



[D 



7'' 
Searchlight Caribons--!^ Diam., 



JZaz'Tt 



E 



I. 



Searcaliglit Carbons - 1 i^ Diam, 



Tt 




Fig. 115, — Carbon Resistance for A. C. Rail Tests. 



the construction of a special type of wattmeter for this pur- 
pose, nor did it seem wise to attempt to employ such an instru- 
ment. It was finally decided that the " three voltmeter method '^ 
was the simplest, most straightforward, and most reliable one, 
and therefore best adapted to the purposes of the investigation. 
The question which next arose was that of a suitable non- 



line T 

r£ 



Rail 







Eesistance- 
Fig. 116. — Diagram of Connections for A. C. Rail Tests. 

inductive resistance to be used in connection with this method 
of testing. It was necessary that this resistance should have 
a low value, that it should be capable of carrying a maximum 
current of GOO amperes, and that it should be fairly constant. 
A water rheostat was found to be out of the question, as it was 
undesirable from the standpoint of exhibitors. The resistance 



ALTERNATING CURRENT LOSSES 309 

finally decided upon consisted of four large search-light carbons 
which were connected in parallel. These carbons were capable 
of carrying a current of 150 amperes each without excessive 
heating, making the total carrying capacity 600 for the four 
carbons in parallel. Connections were made to the ends of the 
carbons by means of gas caps which were soldered to the car- 
bons, as shown in Fig. 115. The carbons were placed approxi- 
mately four inches between centers, and the end connections to 
the gas caps were made by means of large copper straps. The 
resistance of this piece of apparatus was about 0.003 ohm 
when a current of 600 amperes was flowing. 

In taking the readings for power measurements by the three- 
voltmeter method, the circuit and connections to instruments 
were as show^n in Fig. 116. It will be seen that the rail is con- 
sidered as the inductive resistance, while the ammeter shimt 
and carbon resistance together are the non-inductive resistance. 
The pressure measurements taken were the pressure across the 
rail, the pressure across the ammeter shunt, and the carbon 
resistance combined, and the total pressure across the rail, the 
ammeter shunt, and the carbon resistance in series. The cur- 
rent flowing in the circuit was obtained directly from the am- 
meter reading. 

If E^ = the total pressure, 

E^ = the pressure across the inductive resistance, 
E^ = the pressure across the non-inductive resistance, 
/ = the current flowing in the circuit, 
and R = the non-inductive resistance, 

the relations existing between these various quantities are 
as shown in Fig. 117. The current is in phase wdth the pres- 
sure across the non-inductive resistance, and lags behind the 
pressure of the inductive resistance. The total pressure is the 
vector sum of the pressures across the individual parts of the 
circuit, as shown in the diagram. This general relation gives 
immediately the relative phase position of the current and the 
pressure across the inductive portion of the circuit. The angle 
of phase difference is represented by the Greek letter a. 



400 ELECTRIC RAILWAY TEST COMMISSION 

It is seen from this brief description that the object of insert- 
ing the non-inductive resistance into the circuit is to obtain 
three interrelated voltmeter readings, one of which is in phase 
with the current. 

If the value of the current and pressure across the rail and 
their phase relation are known, the power lost in the rail is ex- 
pressed by the equation, 

P = E^I cos a. 

The value of the cosine of the angle a is readily obtained if 
the three pressures which form the triangle are known. The 
final expression for the power lost in the inductive part of the 
circuit is, f^ — F^ — F^ 

2R 

Temperature Measurements. 

Thermometers were placed at different points along the rail, 
both above and below, and the bulbs were inclosed in small 
pasteboard boxes filled with waste to prevent radiation of the 
heat. Readings both of these thermometers and of ther- 
mometers suspended in the air near the rail, were taken at 
frequent intervals. 

Data Sheets. 

In recording the measurements of all quantities connected 
with the tests a blank form, similar to that shown in Fig. 118, 
was used. 

Calibration of Instruments. 

While it would be inferred that proper calibration of instru- 
ments was made, it is considered desirable to make special men- 
tion of this matter in connection with the present series of tests 
for the reason that the methods of measurement employed re- 
quired the most careful calibration. The National Bureau of 
Standards rendered great assistance in this connection. In 
addition to calibrating the various electrical instrimients, 
it also obtained for the Executive Committee the ratios of trans- 



ALTERNATING CURRENT LOSSES 



401 



formation of the pressure transformer under all the conditions 
of the tests. As the transformer was operated at abnor- 
mally low pressures, the ratio of transformation varied con- 
siderably with the pressure. However, by obtaining ratios of 
transformation for the different frequencies and the different 
pressures employed, it was possible to correct for such errors 
with a very fair degree of accuracy. 

WORKING UP THE RESULTS. 

After proper correction, all the results of the tests and 
deductions therefrom, were entered 
on sheets especially prepared for 
the purpose. The data were immedi- 
ately put into graphical form, as this 
best made possible a comparison of the 
various elements. It was foimd, in 
part, to be unnecessary to prepare 
elaborate tables from the data, as the 
graphical presentation renders the in- 
formation accessible and the detection 
of error easy. Unfortunately, it has 
been found impracticable to include 
all of the graphical results in the 
Report. The charts for the rail sec- 
tions are included, but only selected 
tabular results are given for the special 
sections. 

Results of the Tests. 

Test No. 38. Fifty-Six Pound Tee-Rail. — This rail has 
a cross-section as shown in Fig. 119, an area of 5.7 square inches, 
and a weight of 56 lbs. per yard. The distance between the 
contact points was 26.07 ft. 

Table LVII shows the magnetic properties of this rail, the 
tests of magnetic properties having been made for the Executive 
Committee through the courtesy of Professor J. W. Shuster and 
the University of Wisconsin. 




Fig. 117. — Vector Diagram of Three 
Voltmeter Power Measurements. 
A. C. Rail Tests. 



402 



ELECTRIC RAILWAY TEST COMMISSION 



Table LVII. — Test No. 38. — Magnetic Properties of Fifty-Six Pound 

Tee-Rail, 



B. 


H. 


M. 


2,000 


5.63 


353 


4,000 


7.45 


547 


6,000 


9.45 


635 


8,000 


11.90 


672 


10,000 


16.10 


621 


11,000 


19.50 


564 


13,000 


27.85 


468 


14,000 


33.60 


418 


15,000 


42.70 


352 


16,000 


58.30 


275 


16,480 

— 1 ^ 


66.40 


248 



Date' 3504 Data sheet NOi 

•ELECTRIC RAILWAY TEST COMMISSION _^ 



Log and calculations of Tests to determine 
XOSSES IN STEEL BAILS witb. Alternating CvTrrent 



/ 



Eail Data '^'Material Length ft 

Shape Area Sq.-in'^ 

Weight per yd, .-_ lbs. 

'D.C RESISTANCE and Temp. Coeflf. 



Amp. 


volts 


Temp 


Temp. Co. 











































































































































A. C.Losse 
















VOLTS 


AMP 


Act. 
freq. 


Watts 


Power 
Factor 


A. C. 
Drop 












in.non- 
ind.res. 


in rail 


Total 


Total 


per 
sq.in. 


B.C. 
Drop 











































































































































































































































































































































































































































































































































































































































Instruments used: 



OBSERVERS 

Fig. 118. —Blank Form for Taking A. C. Rati Test Data, 



ALTEMATim CtiMENT LOSSES 



40^ 



The results of the tests made in Test No. 38 are shown in Figs. 
120 to 127, inclusive. 

Fig. 120 shows the results of runs Nos. 1 to 4 in this series. 
The diagrams on the left-hand side of the page give the data 
showing the variations of rail drop, power factor, and ratio of 
impedance to D.C. resistance for various currents. The dia- 
grams on the right side of the page show the variation of tem- 
perature with time. The temperature readings were obtained 
by a separate series of tests in which the current was main- 
tained at approximately 600 
amperes imtil the tempera- |^ 

tures had attained steady 
values. The temperature 
curVes show not only the 
rise in temperature with 
time, but they give data for 
obtaining the temperature 
coefficients of the rail sec- 
tions. 

Fig. 121 show^s the similar 
data for runs Nos. 5 to 8. 
It will be noted that no tem- 
perature data are given for 
the lowest frequency, as it 
was impracticable to main- 
tain the current at this frequency for a sufficient length of time 
to obtain the data. From these curves it is possible to obtain 
a number of "cross" curves showing the interrelation of the 
several variables of the tests. , 

Fig. 122 shows the volts drop per mile of continuous rail 
plotted against frequency for the given currents, the frequency 
being varied from 10 to 60 cycles. 

Fig. 123 shows the volts drop per mile of continuous rail 
plotted against current for the given frequencies, the current 
being varied from 50 to 600 amperes. A curve for zero fre- 
quency is also shown in this diagram. This curve sheet con- 




Fig. 119. —Section of 55 lb. Rail A. C. Tests. 



404 



ELECTRiC^kAILWAY TEST COMMISSION 



a 80 

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Fig, 120. — General Data Runs, I to 4, 66 lb. Rail, A, C, Rail Tests. 



ALTERNATING CURRENT LOSSES 



405 




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60 

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Fig, 121, — General Data Runs, 5 to 8. 56 lb. Rail, A. C. Rail Tests. 



406 



ELECTRIC RAILWAY TEST COMMISSION 



tains the same data as the preceding one, except that the fre- 
quency has been given prominence instead of the current. 

Fig. 124 shows the ratio of (A.C.) impedance to (D.C.) resis- 
tance, plotted against frequency. While these data do not yield 
as smooth curves as those shown in the preceding sheet, the 



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Fig. 122. — Frequency Drop Curves, 56 lb. Rail, A . C. Rail Tests. 

curves illustrate the general tendency of this ratio to increase 
with the frequency. 

Fig. 125 shows the same ratio plotted against amperes per 
rail, the frequency remaining constant for a given curve. 

Fig. 126 shows the relation of the power losses and the fre- 
quency with given currents, while Fig. 127 shows the relation 
of the power losses and the current for fixed frequencies. 



ALTERNATING CURRENT LOSSES 



407 



Test No. 39. Eighty-Pound Tee-Rail. — This rail had the 
cross-section shown in Fig. 128, an area of 7.84 sq. in., and a 
weight of 80 lbs. per yard. The distance between contact 
points was 27.83 ft. 



























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Fig. 123. — Current Drop Curves, 56 lb. Rail, A. C. Rail Tests. 



The magnetic properties of this rail are shown in Table LVIII, 
the data for which, as in the case of the preceding test, were 
obtained by special tests made by Professor J. W. Shuster at 
the University of Wisconsin. 



408 



ELECTRIC RAILWAY TEST COMMISSION 



Table LVIII. — Test No. 39. — Magnetic Properties of Eighty-Pound 

Tee-Rail. 



B. 


H. 


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496 


4,000 


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667 


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773 


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657 


12,000 


20.00 


600 


13,000 


24.30 


542 


14,000 


29.15 


478 


15,000 


37.80 


497 


16,000 


53.00 


308 


16,500 


62.00 


266 



The results of these tests are shown in Figs. 129 to 135. 
Fig. 129 shows the general electrical data for the entire series 
of runs, no special temperature runs having been made with 



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Fig. 124.— Frequency Ratio Curves, 56 lb. Rail, A. C. Rail Tests. 

this section. The relations of the several variables have been 
placed in the form of " cross " curves, as in the preceding tests, 
and these are shown in Figs. 130 to 135, 



ALTERNATING CURRENT LOSSES 



409 



Fig. 130 shows the relation between volts drop per mile of 
continuous rail and the frequency, for the various given values 
of the current. 

Fig. 131 shows the same data in reverse form; that is, the 
variation of volts drop per mile of continuous rail with the 













































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Fig. 125. — Current Ratio Curves, 55 lb. Rail, A. C. Rail Tests. 

amperes per rail, for the several given frequencies, including 
zero frequency or continuous current. 

Fig. 132 shows the relation of the ratio of impedance to 
D.C. resistance and the frequency, for given values of current; 
while Fig. 133 shows the same ratio compared with the current, 



410 



ELECTRIC RAILWAY TEST COMMISSION 



for several given values of frequency. The data shown are 
somewhat inconclusive as far as high current densities are 



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F/gr. 126. — Frequency Power Curves, 56 lb. rail, A. C. Rail Tests. 

concerned, but they serve to show the general relation of the 
variables. 

Figs. 134 and 135 give the power loss data for the several 
currents and' frequencies per mile of continuous rail. 




360 



400 450 500 

Amperes per Kail 



350 



60Q 



Fig. 127, — Current Power Curves, 56 Itf. Rails, A. 0. Rail Tests. 



ALTERNATING CURRENT LOSSES 



411 



Tests Nos. 40 to 44. Square, Round, and Pipe Sections. 
— The limits of this Report have not permitted of a graphical 
presentation of the results of the tests upon sections other 
than standard rail sections. The results of the latter tests 
are not as satisfactory as those upon standard rail sections; 
the Executive Committee being obliged to use the material 
which could be most readily obtained. As several of these 
sections were in short lengths and of hard steel, only general 




Fig. 128.— Section of 80 lb. Rail, A C. Rail Tests. 



deductions can be made from the results. It was found im- 
possible to get satisfactory readings of power factor in all cases, 
and especially with the very short lengths of some of the sections. 
The data, therefore, are not complete, but enough work was 
done to give a general idea of the relation of the losses to the 
shape of the section. The results of these tests are presented 
in tables LIX to LXIII, inclusive. The tables are arranged for 
the different sections in the order of the frequencies. 



412 



ELECTRIC RAILWAY TEST COMMISSION 



S 80 

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r/gr. t29. — General Data, 80 lb. Rail, A. C. Rail Tests, 



ALTERNATING CURRENT LOSSES 



413 






VoltB drop per mae of eontinuoue rail 

St o K S 



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Volts drop per mile of eontinuoue rail 




414 



ELECTRIC RAILWAY TEST COMMISSION 




aouB^BTsaa 'a'd ov aauvpacluii j o gi^?a 




WUB^Btaaa '0 a Q^ aauBpodtui jo ot!>Ba 



ALTERNATING CURRENT LOSSES 



415 



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1 1 











10 



50 



60 



20 30 40 

Cycles per second 

F\g, 134— Frequency Power Curijes. 80 lb, Rail. A. C. Tests. 




350 



400 450 500 

Amperes per Rail 



6tK) 



Fig. 135. — Current Power Curves, 80 lb. Rail. A. C. Tests. 



416 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 40. 

Table LIX. — A.C. Losses in Sqvure Section. 

DiAM. 2.51 In. Area 6.295 Sq. In. Length 8.562 Ft. 

Frequency, 10 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 

TO A.C. 

Resistance. 


526 


0.491 


108 


0.00094 


7.9 


421 


0.393 


141 


0.00094 


7.9 


316 


0.292 


74 


0.00092 


7.8 


263 


0.233 


50 


0.00089 


7.5 


210 


0.189 


31 


0.00090 


7.6 


153 


0.132 


15 


0.00086 


7.3 


103 


0.069 


6 


0.00067 


5.7 


78 


0.048 


2 


0.00062 


5.2 





Frequency, 15 Cycles per Second. 




621 


0.693 


322 


0.00110 


9.3 


526 


0.578 


258 


0.00110 


9.3 


421 


0.497 


158 


0.00118 


10.0 


316 


0.317 


99 


0.00100 


8.5 


263 


0.314 


64 


0.00119 


10.1 


210 


0.243 


38 


0.00116 


9.8 


153 


0.181 


20 


0.00118 


10.0 


103 


0.099 


8 


0.00096 


8.1 


78 


0.063 


3 


0.00080 


6.7 


52 


0.042 


0.8 


0.00081 


6.9 





Frequency, 20 Cycles per Second. 




621 


0.796 


404 


0.00126 


8.6 


526 


0.704 


289 


0.00134 


8.8 


421 


0.572 


220 


0.00136 


11.5 


316 


0.452 


119 


0.00143 


11.2 


263 


0.376 


82 


0.00143 


12.1 


210 


0.297 


46 


0.00141 


12.0 


153 


0.211 


24 


0.00138 


11.7 


103 


0.122 


10 


0.00118 


10.0 


78 


0.066 


5 


0.00085 


7.2 


52 


0.046 


1 


0.00089 


7.5 





Frequency, 25 Cycles per Second. 




621 


0.926 


446 


0.00147 


12.4 


526 


0.825 


314 


0.00157 


13.2 


421 


0.680 


202 


0.00161 


13.6 


316 


0.516 


142 


0.00163 


13.8 


263 


0.428 


101 


0.00163 


13.8 


210 


0.336 


55 


0.00160 


13.5 


153 


0.168 


23 


0.00109 


7.9 



ALTERNATING CURRENT LOSSES 



417 



Frequency, 30 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance. 

TO A.C. 

Resistance. 


621 


1.007 


573 


0.00160 


13.5 


526 


0.870 


362 


0.00165 


14.0 


421 


0.727 


239 


0.00173 


14.6 


316 


0.558 


156 


0.00177 


14.9 


263 


0.478 


120 


0.00182 


15.4 


153 


0.271 


38 


0.00177 


14.9 


103 


0.160 


13 


0.00156 


13.2 


78 


0.103 


6 


0.00132 


11.1 


52 


0.049 


2 


0.00099 


8.0 





Frequency, 40 Cycles per Second. 




621 


1.325 


588 


0.00210 


17.8 


526 


1.162 


420 


0.00221 


18.7 


421 


0.960 


278 


0.00228 


19.3 


316 


0.707 


188 


0.00225 


19.0 


263 


0.590 


120 


0.00224 


18.9 


210 


0.465 


72 


0.00221 


18.7 


153 


0.348 


40 


0.00227 


19.2 


103 


0.208 


15 


0.00202 


17.1 


78 


0.130 


8 


0.00167 


14.1 


52 


0.073 


3 


0.00140 


11.8 



Frequency, 50 Cycles per Second. 



526 


1.260 


474 


0.00239 


20.2 


421 


1.053 


310 


0.00250 


21.2 


316 


0.780 


166 


0.00247 


20.8 


263 


0.642 


125 


0.00243 


20.7 


210 


0.521 


86 


0.00248 


20.0 


153 


0.406 


47 


0.00265 


22.4 


103 


0.247 


19 


0.00239 


20.2 


78 


0.167 


11 


0.00214 


18.1 


52 


0.089 


4 


0.00172 


14.5 





Frequency, 60 Cycles per Second. 




621 


1.560 


715 


0.00251 


21.2 


526 


1.380 


509 


0.00262 


22.2 


421 


1.175 


347 


0.00279 


23.6 


316 


0.843 


221 


0.00266 


22.5 


263 


0.730 


149 


0.00278 


23.5 


210 


0.589 


78 


0.00280 


23.7 


153 


0.475 


61 


0.00310 


22.1 


103 


0.296 


25 


0.00287 


24.3 


78 


0.196 


12 


0.00252 


21.3 


52 


0.101 


5 


0.00194 


16.4 



418 



ELECTRIC RAILWAY TEST COMMISSIOM 



Test No. 41. 

Table LX. — A.C. Losses in Round Section. 

DiAM. 1.5 In. Area 7.068 Sq. In. Length 8.16 Ft. 

Frequency, 10 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 
TO D.C. 

Resistance. 


526 


0.506 


154 


0.00096 


9.0 


421 


0.420 


171 


0.00100 


9.4 


316 


0.352 


75 


0.00111 


10.5 


263 


0.286 


55 


0.00109 


10.3 


210 


0.204 


35 


0.00097 


9.1 


153 


0.153 


19 


0.00100 


9.4 


103 


0.096 


7 


0.00094 


8.8 


78 


0.061 


4 


0.00078 


7.3 





Frequency, 15 Cycles per Second. 




631 


0.720 


318 


0.00114 


10.7 


526 


0.637 


201 


0.00121 


11.4 


421 


0.543 


147 


0.00127 


11.9 


316 


0.436 


89 


0.00138 


13.0 


263 


0.371 


62 


0.00141 


13.3 


210 


0.203 


45 


0.00130 


12.2 


103 


0.132 


10 


0.00128 


12.1 


78 


0.083 


5 


0.00106 


10.0 


52 


0.051 


1 


0.00099 


9.3 





Frequency, 20 Cycles per Second. 




631 


0.820 


354 


0.00130 


12.2 


526 


0.725 


247 


0.00138 


13.0 


421 


0.596 


199 


0.00141 


13.3 


316 


0.482 


101 


0.00152 


14.3 


263 


0.384 


70 


0.00146 


13.7 


210 


0.308 


52 


0.00146 


13.7 


153 


0.241 


26 


00.0158 


14.9 


103 


0.145 


11 


0.00140 


13.2 


78 


0.087 


5 


0.00112 


10.5 


52 


0.056 


2 


0.00108 


10.2 





Frequency, 25 Cycles per Second. 




631 


0.958 


412 


0.00152 


14.3 


526 


0.843 


295 


0.00160 


15.1 


421 


0.712 


188 


0.00169 


15.9 


316 


0.553 


128 


0.00175 


16.5 


263 


0.464 


97 


0.00176 


16.6 


210 


0.364 


57 


0.00173 


16.3 


153 


0.275 


31 


0.00180 


16.9 


103 


0.170 


13 


0.00165 


15.5 


78 


0.116 


7 


0.00149 


14.0 


52 


0.057 


2 


0.00110 


10.4 



I 



ALTERNATING CURRENT LOSSES 
Frequency, 30 Cycles per Second. 



419 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 

TO D.C. 

Resistance. 


631 


1.060 


439 


0.00168 


15.8 


526 


0.940 


312 


0.00178 


16.8 


421 


0.795 


210 


0.00189 


17.8 


316 


0.627 


145 


0.00198 


18.6 


263 


0.523 


111 


0.00199 


18.7 


210 


0.424 


67 


0.00202 


19.0 


153 


0.314 


34 


0.00205 


19.3 


103 


0.190 


14 


0.00185 


17.4 


78 


0.125 


7 


0.00160 


15.1 


52 


0.071 


2 


0.00137 


12.8 





Frequency, 40 Cycles per Second. 




631 


1.300 


529 


0.00206 


19.4 


526 


1.147 


345 


0.00218 


20.5 


421 


0.959 


235 


0.00227 


21.4 


316 


0.712 


187 


0.00225 


21.2 


263 


0.613 


118 


0.00233 


21.9 


210 


0.494 


74 


0.00235 


22.1 


153 


0.373 


45 


0.00244 


23.0 


103 


0.234 


17 


0.00227 


21.3 


78 


0.154 


10 


0.00197 


18.5 


52 


0.080 


3 


0.00154 


14.5 





Frequency, 50 Cycles per Second. 




631 


1.445 


569 


0.00229 


21.5 


526 


1.274 


430 


0.00242 


22.8 


421 


1.074 


265 


0.00256 


24.1 


316 


0.803 


187 


0.00254 


23.9 


263 


675 


111 


0.00256 


24.1 


210 


0.561 


85 


0.00267 


25.1 


153 


0.435 


52 


0.00284 


26.7 


103 


0.269 


20 


0.00261 


24.6 


78 


0.176 


11 


0.00225 


21.2 


52 


0.089 


4 


0.00172 


16.2 





Frequency, 60 Cycles per Second. 




631 


1.600 


690 


0.00253 


24.1 


526 


1.400 


465 


0.00266 


25.3 


421 


1.180 


317 


0.00280 


26.7 


316 


0.880 


206 


0.00278 


26.4 


263 


0.740 


147 


0.00281 


26.8 


210 


0.630 


89 


0.00300 


28.6 


153 


0.520 


59 


0.00340 


32.4 


103 


0.320 


27 


0.00310 


29.5 


78 


0.216 


14 


0.00278 


26.5 


52 


0.151 


3 


0.00290 


27.6 



420 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 42. 

Table LXI. — A.C. Losses in Round Section, 

DiAM. 1.25 In. Area 4.97 Sq. Ft. Length 4.97 Ft. 

Frequency, 10 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance. 

TO D.C. 

Resistance. 


526 


0.575 


176 


0.00109 


7.9 


421 


0.461 


123 


0.00109 


7.9 


316 


0.383 


75 


0.00121 


8.8 


263 


0.328 


64 


0.00125 


9.1 


210 


0.240 


42 


0.00114 


8.3 


153 


0.176 


17 


0.00115 


8.3 


103 


0.099 


7 


0.00096 


6.9 


78 


0.069 


4 


0.00088 


6.4 


52 


0.058 


0.8 


0.00110 


8.0 





Frequency, 15 Cycles per Second. 




631 


0.780 


292 


0.00124 


9.1 


526 


0.695 


214 


0.00132 


9.7 


421 


0.582 


134 


0.00138 


10.1 


316 


0.486 


96 


0.00154 


11.3 


263 


0.435 


64 


0.00165 


12.1 


210 


0.314 


49 


0.00150 


11.0 


103 


0.139 


8 


0.00135 


9.9 


-78 


0.095 


4 


0.00122 


9.0 


52 


0.052 


1 


0.00100 


7.4 





Frequency, 20 Cycles per Second. 




631 


0.908 


344 


0.00144 


10.7 


526 


0.797 


232 


0.00151 


11.2 


421 


0.658 


213 


0.00156 


11.6 


316 


0.545 


110 


0.00172 


12.8 


263 


0.398 


87 


0.00151 


11.2 


210 


0.356 


37 


0.00170 


12.6 


103 


0.162 


11 


0.00157 


11.6 


78 


0.110 


5 


0.00141 


11.5 


52 


0.060 


2 


0.00115 


8.5 





Frequency, 25 Cycles per Second. 




631 


1.033 


410 


0.00164 


12.1 


526 


0.920 


299 


0.00175 


12.9 


421 


0.778 


203 


0.00185 


13.7 


316 


0.613 


137 


0.00194 


14.3 


263 


0.519 


90 


0.00197 


14.5 


210 


0.412 


73 


0.00196 


14.5 


153 


0.304 


31 


0.00199 


14.7 


103 


0.189 


13 


0.00183 


13.5 


78 


0.128 


6 


0.00164 


12.1 


52 


0.071 


2 


0.00136 


10.0 



ALTERNATING CURRENT LOSSES 



421 



Frequency, 30 Cycles per Second. 











Ratio Im- 


Current, 


Volts. 


Watts. 


Impedance, 


pedance 

TO D.C. 

Reslstance. 


631 


1.153 


461 


0.00183 


13.4 


526 


1.023 


335 


0.00195 


14.3 


421 


0.870 


243 


0.00206 


15.1 


316 


0.696 


151 


0.00220 


16.1 


263 


0.585 


107 


0.00222 


16.3 


210 


0.476 


72 


0.00227 


16.7 


153 


0.343 


38 


0.00224 


16.4 


103 


0.211 


14 


0.00205 


15.0 


78 


0.147 


6 


0.00187 


13.7 


52 


0.076 


2 


0.00146 


10.7 





Frequency, 40 Cycles per Second. 




631 


1.390 


560 


0.00220 


16.1 


526 


1.550 


381 


0.00234 


17.1 


421 


1.030 


272 


0.00245 


18.0 


316 


0.800 


167 


0.00253 


18.5 


263 


0.655 


133 


0.00249 


18.2 


210 


0.543 


85 


0.00259 


19.0 


153 


0.400 


49 


0.00261 


19.1 


103 


. 255 


16 


0.00248 


17.6 


78 


0.172 


7 


0.00220 


16.1 • 





Frequency, 50 Cycles per Second. 




631 


1.530 


605 


0.00244 


17.8 


526 


1.360 


441 


0.00258 


18.8 


421 


1.150 


300 


0.00273 


19.9 


316 


0.870 


199 


0.00275 


20.1 


263 


0.735 


139 


0.00280 


20.4 


153 


0.463 


55 


0.00302 


20.0 


103 


0.298 


20 


0.00289 


21.1 


78 


0.198 


11 


0.00254 


18.5 


52 


0.098 


3 


0.00189 


13.8 





Frequency, 60 Cycles per Second. 




631 


1.710 


673 


0.00271 


20.0 


526 


1.500 


500 


0.00285 


20.9 


421 


1.260 


359 


0.00301 


22.1 


316 


0.940 


207 


0.00298 


21.9 


263 


0.800 


163 


0.00304 


22.4 


210 


0.695 


101 


0.00330 


24.3 


153 


0.520 


63 


0.00340 


25.0 


103 


0.347 


22 


0.00336 


24.7 


78 


0.236 


13 


0.00298 


21.9 


52 


0.118 


4 


0.00227 


16.7 



422 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 43. 

Table LXII. — A.C. Losses in Square Section. 

DiAM. 2.01 In. Area 4.05 Sq. In. Length 6.948 Ft. 

Frequency, 10 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 
TO D.C. 

Resistance. 


526 


0.575 


249 


0.00109 


8.9 


421 


0.490 


172 


0.00116 


9.5 


316 


0.326 


102 


0.00103 


8.5 


263 


0.302 


78 


0.00115 


9.4 


210 


0.243 


52 


0.00116 


9.5 


153 


0.176 


24 


0.00115 


9.4 


103 


0.117 


13 


0.00114 


9.4 


78 


0.085 


7 


0.00109 


8.9 


52 


0.052 


3 


0.00101 


8.3 





Frequency, 15 Cycles per Second. 




631 


0.776 


471 


0.00123 


10.1 


526 


0.655 


358 


0.00124 


10.2 


421 


0.583 


225 


0.00138 


11.3 


316 


0.422 


137 


0.00133 


10.9 


263 


0.359 


102 


0.00137 


11.3 


210 


0.253 


57 


0.00121 


9.9 


153 


0.181 


29 


0.00118 


9.7 


103 


0.121 


13 


0.00117 


9.6 


78 


0.083 


10 


0.00106 


8.7 


52 


0.051 


3 


0.00099 


8.1 



Frequency, 20 Cycles per Second. 



631 


0.852 


512 


0.00135 


11.1 


526 


0.526 


198 


0.00100 


8.3 


421 


0.570 


240 


0.00135 


11.1 


316 


0.427 


135 


0.00135 


11.1 


263 


0.371 


94 


0.00141 


11.7 


210 


0.273 


59 


0.00130 


10.7 


153 


0.198 


29 


0.00129 


10.7 


103 


0.130 


15 


0.00126 


10.4 


78 


0.096 


8 


0.00124 


10.2 


52 


0.061 


3 


0.00118 


9.8 





Frequency, 25 Cycles per Second. 




526 


0.767 


366 


0.00146 


12.0 


421 


0.615 


245 


0.00146 


12.0 


316 


0.457 


134 


0.00144 


11.8 


263 


0.383 


74 


0.00146 


12.0 


210 


0.282 


59 


0.00135 


11.1 


153 


0.209 


33 


0.00136 


11.2 


103 


0.135 


15 


0.00131 


10.8 


78 


0.102 


9 


0.00131 


10.8 


52 


0.060 


3 


0.00127 


10,4 



ALTERNATING CURRENT LOSSES 



423 



Frequency, 30 Cycles per Second. 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 
TO D. C. 

Resistance. 


631 


0.995 


610 


0.00158 


13.1 


526 


0.834 


406 


0.00158 


13.1 


421 


0.730 


279 


0.00173 


14.3 


316 


0.631 


189 


0.00200 


16.6 


263 


0.575 


154 


0.00218 


18.1 


210 


0.489 


100 


0.00233 


19.3 





Frequency, 40 Cycles per Second. 




631 


1.092 


524 


0.00173 


13.9 


526 


0.961 


436 


0.00183 


14.7 


421 


0.778 


300 


0.00185 


14.9 


316 


0.641 


202 


0.00203 


16.3 


263 


0.577 


159 


0.00219 


17.6 


210 


0.470 


119 


0.00224 


18.0 





Frequency, 50 Cycles per Second. 




631 


1.223 


620 


0.00194 


15.4 


526 


1.018 


470 


0.00194 


15.4 


421 


0.838 


335 


0.00199 


15.8 


316 


0.693 


202 


0.00219 


17.4 


263 


0.595 


153 


0.00226 


18.0 


210 


0.534 


112 


0.00254 


20.2 


153 


0.500 


80 


0.00327 


26.0 





Frequency, 60 Cycles per Second. 




631 


1.355 


717 


0.00215 


17.7 


526 


1 . 145 


499 


0.00218 


17.9 


421 


0.956 


352 


0.00227 


18.6 


316 


0.706 


235 


0.00223 


18.3 


263 


0.645 


159 


0.00245 


20.1 


210 


0.538 


112 


0.00256 


21.0 



424 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 44. 

Table LXIII. — A.C. Losses in Pipe Section. 

Area 2.27 Sq. In. Length 18.427 Ft. Inside Diameter ' 3.07 In. 
Outside Diameter 3.51 In. 



Frequency, 10 Cycles per Second. 











Ratio Im- 


Current, 


Volts. 


Watts. 


Impedance. 


pedance 

TO D.C. 

Resistance. 


474 


1.150 


424 


0.00524 


7.4 


421 


1.068 


305 


0.00254 


3.6 


316 


0.845 


183 


0.00267 


3.8 


263 


0.725 


129 


0.00275 


3.9 


210 


0.598 


87 


0.00285 


4.0 


153 


0.492 


55 


0.00322 


4.5 


103 


0.382 


25 


0.00371 


5.2 


78 


0.258 


19 


0.00.331 


4.7 


52 


0.141 


7 


0.00272 


3.8 





Frequency, 15 Cycles per Second. 




631 


1.615 


766 


0.00256 


3.6 


526 


1.483 


572 


0.00282 


4.0 


421 


1.283 


343 


0.00305 


4.3 


263 


0.897 


186 


0.00341 


4.8 


210 


0.760 


123 


0.00362 


5.1 


103 


0.461 


34 


0.00448 


6.3 


78 


0.344 


20 


0.00428 


6.0 





Frequency, 20 Cycles per Second. 




631 


1.900 


883 


0.00310 


4.3 


526 


1.670 


670 


0.00318 


4.4 


421 


1.510 


470 


0.00358 


5.0 


316 


1.220 


298 


0.00386 


5.4 


263 


1.080 


214 


0.00410 


5.7 


210 


0.880 


144 


0.00420 


5.8 


153 


0.725 


88 


0.00474 


6.6 


103 


0.518 


40 


0.00503 


7.0 


78 


0.387 


25 


0.00496 


6.9 





Frequency, 25 Cycles per Second. 




631 


2.080 


982 


0.00330 


4.6 


526 


1.880 


764 


0.00358 


5.0 


421 


1.650 


512 


0.00393 


5.5 


316 


1.373 


307 


0.00434 


6.1 


263 


1.175 


240 


0.00447 


6.3 


210 


0.941 


157 


0.00448 


6.3 


153 


0.781 


96 


0.00510 


7.2 


103 


0.572 


49 


0.00555 


7.8 


78 


0.438 


27 


0.00561 


7.9 


52 


0.272 


12 


0.00522 


7.3 



ALTERNATING CURRENT LOSSES 
Frequency, 30 Cycles per Second. 



425 











Ratio Im- 


Current. 


Volts. 


Watts. 


Impedance. 


pedance 
TO D.C. 

Resistance. 


631 


2.310 


1258 


0.00366 


5.0 


526 


2.080 


811 


0.00396 


5.5 


421 


1.830 


581 


0.00435 


6.0 


316 


1.500 


342 


0.00474 


6.5 


263 


1.292 


275 


0.00491 


6.8 


210 


1.058 


175 


0.00504 


7.0 


153 


0.853 


106 


0.00557 


7.7 


103 


0.621 


51 


0.00603 


8.3 


78 


0.467 


29 


0.00599 


8.3 


52 


0.282 


16 


0.00542 


7.5 





Frequency, 40 Cycles per Second. 




631 


2 620 


1595 


0.00416 


5.9 


526 


2.360 


865 


0.00449 


6.4 


421 


2.023 


647 


0.00486 


6.9 


316 


1.674 


402 


0.00529 


7.5 


263 


1.420 


308 


0.00540 


7.7 


210 


1.190 


213 


0.00567 


8.1 


153 


0.950 


117 


0.00621 


8.9 


103 


0.681 


55 


0.00661 


9.4 


78 


0.509 


34 . 


0.00652 


9.S 


52 


0.291 


14 


0.00560 


8.6 





Frequency, 50 Cycles per Second. 




631 


2.030 


1850 


0.00480 


6.5 


526 


2.720 


1382 


0.00516 


7.0 


421 


2.660 


980 


0.00561 


7.6 


316 


1.896 


493 


0.00600 


8.1 


263 


1.667 


298 


0.00634 


8.5 


210 


1.372 


225 


0.00654 


8.8 


153 


1.100 


146 


0.00719 


9.7 


103 


0.770 


69 


0.00747 


10.1 


78 


0.613 


42 


0.00785 


10.6 


52 


0.369 


16 


0.00710 


9.6 





Frequency, 60 Cycles per Second. 




631 


3.280 


1960 


0.00520 


7.3 


526 


2.960 


1510 


0.00562 


7.9 


421 


2.540 


845 


0.00603 


8.5 


316 


2.040 


508 


0.00645 


9.1 


263 


1.790 


374 


0.00680 


9.6 


210 


1.560 


221 


0.00743 


10.5 


153 


1.170 


151 


0.00765 


10.8 


103 


0.890 


79 


0.00860 


12.1 


78 


0.666 


43 


0.00853 


12.0 


52 


0.518 


16 


0.00765 


10.8 



426 ELECTRIC RAILWAY TEST COMMISSION 

Discussion of Results. 

Data on Light Rail Section, Test No. 38. 

Rail Drop Data. — An inspection of the rail drop curves 
shows that the drop increases almost proportionately with the 
current at all frequencies. A slight tendency toward curvature is 
noticed both at the lower and the upper parts of the curve. The 
same characteristic form is preserved for the various frequencies. 
The curves show the variations over a wide range of frequency 
and current. The results illustrate, therefore, what may be 
expected under average conditions of operation. As is to be 
anticipated, the drop is very much greater at the high fre- 
quencies, and the curves show that with a current of 300 amperes 
per rail, a frequency of 50 cycles produces approximately twice 
the drop which is caused by a frequency at 15 cycles. This is 
due to the fact that, at the high frequencies, the current is driven 
to the surface of the rail, and the actual electric resistance is 
thereby greatly increased. The fact that this drop is largely due 
to an mcrease of resistance is evident from a study of the power- 
factor curves, which show that, roughly speaking, the power 
factor in the rail is not far from 80 per cent. The inductive 
effect in the rail is, therefore, small, compared with the "skin 
effect" produced by the driving of the current to the surface 
of the rail. 

The Impedance-Resistance Curves. — The curves showing 
the ratio of alternating current impedance to the D.C. resistance 
have a characteristic form, which is preserved throughout the 
entire range of the tests. At very low values of the current, 
the ratio approaches unity, especially in the low frequency 
tests. It will be noted that at the low values of current, 
the power factor corresponding to the drop, is somewhat 
reduced, showing that this drop contains a larger inductive 
component than at the high values of current. This is due to 
the fact that at low current densities, the current is more uni- 
formly distributed over the section of the rail, and, therefore, 
more magnetic flux surrounds the current, in proportion to the 



ALTERNATING CURRENT LOSSES 



427 



current flowing, than when the latter is nearer to the surface 
of the rail. Difference in permeability with changes in current 
also affect the inductive component of the rail drop. This is 
further emphasized by the tendency of the power factor to in- 
crease at low current density with an increase in frequency. As 
an example of this, it is noted that at 100 am^peres, 60 cycles, 
the power factor is slightly over one-half its value at 500 am- 
peres; while at 15 cycles the power factor at 100 amperes and 500 
amperes is nearly the same. This shows that in general the 
inductance of the rail is high at the low current densities, while 
at high current densities it is low; and, further, that this differ- 
ence is greater at the high frequencies than it is at the low fre- 
quencies. The time available in preparation of this Report did 
not permit of a critical study of these relations, but from the 
curves it is possible to make a number of important deductions. 

The ratio curves show a tendency to attain a. constant value 
at a current slightly above 400 amperes in the rail, and this is 
also true in the case of the larger rail described in Test No. 39. 
At and above this point it is evident that the conditions in the 
rail are such that the current is distributed in a thin layer on 
the surface of the rail, and that the magnetic flux developed 
in the rail cannot further concentrate the current. 

Power-Factor Curves. — As has been previously stated, 
the data from which the power-factor curves were plotted, are 
not sufficiently accurate to warrant fixed conclusions regard- 
ing the matter. However, the number of measurements taken 
was so great, considering the difficulty of making them, and they 
agree so well among themselves, that some deductions may 
safely be made. There is a general tendency for the power 
factor to increase with an increase in the current, this ten- 
dency to increase being greater at high frequencies than at low. 
This is in accordance with what is to be expected, for, in the 
first place, a high frequency has greater power to drive the 
current to the surface of the rail, and hence to increase the ohmic 
resistance; and in the second place, to decrease the reactance 
of the rail, as the larger currents reduce the permeability of the 



428 ELECTRIC RAILWAY TEST COMMISSION 

rail, and hence, especially at the higher frequencies, there is a 
proportionally less counter e.m.f. produced in the rail with a 
large current than with a small. 

Temperature Data. — The importance of the temperature 
data in corroborating the deductions drawn from the other 
tests, lies in the fact that since the increased pressure drop is 
accompanied by an increase in the energy loss (resistance, 
eddy current, and hysteresis) in the rail, the pressure drop is 
due in a great part to a loss in the energy which is being trans- 
mitted through the rail, and all such energy losses are directly 
proportional in alternating current working, in their effect upon 
the power factor to the apparent non-inductive resistance of 
the circuit. This is clearly the case, as shown by the tempera- 
ture curves. In the temperature tests, the current was main- 
tained constant at 631 amperes. The curves show that at the 
end of two hours, the temperature had risen as follows: 60 
cycles, 49°; 50 cycles, 47°; 40 cycles, 47° (top of rail only); 30 
cycles, 46°; 25 cycles, 44°; 20 cycles, 42°; 15 cycles, 42°. These 
data were in practically all cases the average of readings taken 
at the top and at the bottom of the rail, the former being in 
most cases considerably greater than the latter. 

The Power Data. — The power curves show in a conclusive 
manner, the considerable losses which are to be expected in 
transmitting currents of any considerable value through a steel 
rail. These losses are greatest at high frequencies, but they 
are large even at low frequencies. In alternating current 
practice, it will be undoubtedly the case that the currents in 
the rails will be smaller than is customary at the present time 
in direct current practice, owing to the higher pressures which 
will be employed; however, even with this decrease in current, 
the loss in the rails is certain to assume considerable proportions. 

Dr.ta on Heavy Rail Section. Test No. 39. 

Rail Drop Data. — In comparing the drop produced in the 
heavy rail with the corresponding value in the light rail, for 
any given current, the surprising fact is noted that with the 



ALTERNATING CURRENT LOSSES 429 

larger rail the drop is greater. This simply shows that, on 
account of the larger value of the total flux in the larger rail, a 
greater counter-e.m.f. is developed at a given frequency, and 
consequently the current is driven to the surface of the rail to 
a greater extent. This result has a most important bearing 
upon the application of steel conductors for alternating cur- 
rents as it indicates that, where the cross-section of a given 
conductor is large compared with the periphery, a greater 
pressure drop results; and that, with a large cross-section and 
a proportionally smaller periphery, the current is more unevenly 
distributed over the cross-sectional surface. 

The Impedance-Resistance Curves. — The impedance- 
resistance curves for the heavy rail show, in general, the same 
tendency which has been already noted in connection with the 
light rail, except that the highest value of the ratio is reached 
at a lower value of the current. Further, the curves seem to 
show a tendency to a slight decrease in the ratio beyond a 
certain maximum value, which occurs at current densities 
between 400 and 500 amperes. This would indicate a condi- 
tion in which the permeability of the rail passes its maximum 
value. While the curves for the light rail do not show this 
tendency, it is quite possible that, had the tests been continued 
further in the direction of increasing the current, such a ten- 
dency might have been indicated. The curvature of the ratio 
curve of the heavy rail section is so consistent that there ap- 
pears to be no question as to the existence of a maximum 
value. 

Power-Factor Curves. — As in the case of the light rail, 
the power-factor data are not conclusive enough to permit 
the drawing of any important deductions, except that in prac- 
tically all cases, the power factor is somewhere between 70 and 
90 per cent. In all cases the power factor is high, and it is 
substantially the same as in the preceding tests, being slightly 
higher in the case of the heavy rail. This naturally follows 
from the increased ohmic resistance in the large rail. 

Temperature Data. — The only temperature data taken in 



430 ELECTRIC RAILWAY TEST COMMISSION 

the runs on the heavy rail were those necessary to determine 
the direct current resistance with various currents, and to de- 
termine the temperature coeJSicient with which to correct for 
the differences in temperature. No special temperature runs 
were made, as it was considered that the data secured for the 
light rail yielded all the necessary information in regard to the 
heating effect of the current. From the data there obtained, 
it is evident that the increased surface of the rail is not suf- 
ficient to radiate the extra heat generated without an increase 
in the temperature. 

The Power Data. — As would naturally follow from the 
higher resistance and power factor in the large rail, the loss 
per mile with a given current and frequency are correspondingly 
greater. 

Data on Square Sections. Tests Nos. 40 and 43. 

While of less importance than the sections previously dis- 
cussed, the square section is sometimes important in case it 
is ever desired to use a third rail conductor for alternating 
currents. 

The square section has a large area compared with its 
periphery, and it should therefore give a fairly large ratio of 
impedance to D.C. resistance. Tables LIX and LXII show 
this to be the case, as the ratio varies between a moderate 
value for the very low frequencies to a very high value at 60 
cycles. As in the case of the large and small rails, the ratio 
of impedance to D.C. resistance is greater with the large sec- 
tion than with the small section. The power loss, however, 
appears to be greater with the smaller section in this case, al- 
though the difference is not very great. This difference is 
quite marked at the low frequencies, while at the high frequen- 
cies the power consumption is more nearly the same in the 
two samples tested. As has been previously explained, the 
samples were of very hard steel, and, as it was impracticable 
to make any magnetic measurements, the difference may easily 
be due to either or both the magnetic and electrical qualities of 
the steel. It would be safer, therefore, to accept these data as 



ALTERNATING CURRENT LOSSES 4gl 

being of a very general nature, and not so accurately com- 
parable as in the case of the two-rail sections, the two round 
sections, and the pipe section. 

Data on Round Sections. Tests Nos. 41 and 42. 
The data for the tests on the round sections compare very 
closely with what is theoretically to be expected; that is, the 
larger section gives the greater ratio of impedance to D.C. 
resistance at all frequencies and at all values of current. The 
explanation of this is the same as in the discussion of the rail 
tests; namely, that with the large section the current is driven 
to the surface of the rail to a greater extent. The round sec- 
tion is, as accords with theory, the poorest one for conducting 
alternating currents, containing as it does the greatest cross- 
sectional area for a given periphery. This is borne out clearly 
in the results, which show that the ratio of impedance to D.C. 
resistance is on the whole, greater than in any of the other 
tests. 

Data on Pipe Section. Test No. 44. 

While the round section is the poorest one from the stand- 
point of alternating current conductivity, the pipe section is 
one of the best, as the iron at the center is removed and there 
is, therefore, less magnetic material in proportion to the surface 
of the conductor. If the pipe were very thin it is evident that 
an alternating current would meet very little more resistance 
than would a direct current. As the pipe in this case had a 
thickness of nearly a quarter of an inch, there was evidently 
sufficient magnetic material to give a considerable "skin'' 
effect. It was, however, much smaller than in any other case, 
and when the impedance is compared with the area it is seen 
to be quite small. Although the actual power loss, as shown 
by the tables, is large, because the number of amperes per 
square inch of area is excessive, the pipe clearly shows its 
superiority as a conductor of alternating current. 



CHAPTER XIII. 
ALTERNATING CURRENT LOSSES IN TRACK. 



Objects of the Tests. 

The principal object of these tests was to ascertain the energy 
losses in an actual stretch of track when subjected to alternating 
current, to observe the effects of varying the strength of these 
currents and their frequency, and to compare the losses with 
those resulting from equivalent direct currents. 

Another object was to determine and compare the losses re- 
sulting when the current flowed in a single rail, in both rails of 
a single track, and in the four rails of a double track. Another 
important matter was the separation of the energy losses 
due to the current flowing in the track rails from the energy 
losses in the overhead construction. 

Synopsis of Results. 

On account of the nature of the results of these tests, it has 
been found very impracticable to summarize the general re- 
sults in a single table. The synopsis at the beginning of this 
chapter is therefore omitted, and the curves found later on in 
the chapter are depended upon to show the scope of the work 
and the results obtained. 

General Conditions of the Tests. 

Chapter XII contains the results of a large number of inves- 
tigations relating to the alternating current losses in steel rails 
and in other steel and iron sections, under different conditions 
of frequency and current density. While it is believed that the 
data and results set forth in that chapter, truly represent the 

432 



ALTERNATING CURRENT LOSSES IN TRACK 433 

losses occurring in single lengths of the various sections tested, 
it has not been considered that tests of this nature necessarily 
represent the losses which would actually occur in the case of 
a constructed track. 

In order to compare the results obtained on individual rail 
lengths with those which might be expected in a constructed 
track, and to furnish additional data of this nature for use in 
alternating current railway installations, a series of investiga- 
tions was carried out on the test tracks lying directly north 
of and parallel to the Palace of Transportation at the St. Louis 
Exposition. 

THE TEST TRACK. 

Fig. 136 gives a plan of the tracks, and shows their position 
relative to the Palace of Transportation and to the tracks of 
the Intramural Railway It is seen that the test tracks were 
two in number, and were situated between the Intramural 
Railway and the north side of the Palace of Transportation, 
and that they ran directly east and west, paralleling the Intra- 
mural tracks. Both test tracks were connected to the Intra- 
mural tracks at the west end, and the north one of the two test 
tracks was connected to the Intramural tracks at the east end. 
The south test track was "dead-ended" at the east end of the 
Palace of Transportation. The stretch of double track was 
about 1200 ft. in length. 

Fig. 136 also shows a cross-sectional sketch giving the gen- 
eral grade levels. It is seen that both of the test tracks were 
somewhat lower than the Intramural tracks, and that the north 
test track level was higher than that of the south test track. 
The difference in level between the two test tracks was ap- 
proximately three feet. The switching and crossing connec- 
tions between the various tracks are also shown in Fig. 136. 

The tracks were laid with 56-lb. Tee rails, A. S. C. E. standard, 
30 ft. lengths, 4 ft. 8J in. gage, and 15 ft. centers, on oak ties 
of standard size, twelve to a rail length, which were set in cinder 
ballast. There were several short stretches of metal ties of 
different makes in the south track. 



iU 



ELECTRIC RAILWAY TEST COMMISSION 



•^001 'PiH •lanuiJis 



•S So- g 



-is 






---^^ 



■fi-SV 




V 



'^.-T 



\^.;p' 



J " 






S5. 









The joints between tracks were 
made with 4-hole angle-bars. Each 
joint was bonded with 'No.OO B &S 
gage copper bond, with a J-inch 
head; which was expanded in the 
web of the rail by means of an iron 
drift pin through the center of the 
head. All bond connections were 
made outside of the angle-bars. 
The rails on each track were cross- 
bonded every 300 ft., and the two 
tracks were cross-bonded every 
500 ft. The bonding was done by 
the American Steel and Wire Com- 
pany, and formed a part of their 
exhibit at the Exposition. 

The overhead material was fur- 
nished by the Wesco Supply Com- 
pany of St. Louis, and was installed 
by the Mechanical and Electrical 
Department of the Exposition Com- 
pany. The poles were wire locked 
swedge- join ted steel tubular poles 
28 ft. long, consisting of three 
sections with diameters of 6, 5, 
and 4 in. respectively. 

The center pole type of construc- 
tion was employed, and it was 
found that the poles were not of 
sufficient length, because of the 
fact that the two tracks were not 
on the same level. They were 
made of sufficient length by driv- 
ing wooden plugs into the bottom 
sections, and allowing these plugs 
to project 2 ft. from the ends of 



ALTERNATING CURRENT LOSSES IN TRACK 435 

the poles. The poles were then placed between the two tracks 
in 6 ft. holes 18 in. in diameter. The holes were filled with 
concrete consisting of two parts of Portland cement and five 
parts of crushed stone. Each pole was equipped with a 
Hercules double bracket made of 1^ in. seamless tubing. The 
Wesco "form M" hangers were iised throughout. The trolley 
wire was No. 00 B & aS gage round wire, and was furnished by 
the American Steel and Wire Company. The north trolley wire 
was 18 ft. above the track, while the height of the south trolley 
wire above the track v/as 20 ft. 

The test track was practically level throughout its entire 
length. While the profile is a matter of minor importance in 
the tests considered in the present chapter, it is of importance 
in connection with the Service, Acceleration, and Braking Tests 
which were made on the single-truck city car and described in 
Chapters II, V, and X of this report. The various tests on this 
car were carried out on the upper or north track, and this track 
was carefully surveyed for the section used in the tests men- 
tioned. It was found that the difference in level was slight, and 
that the grade was approximately 0.2 per cent, the highest part 
being at the west end. 

THE POWER SUPPLY. 

Power was obtained from the exhibit space of the Bullock 
Electric Manufacturing Company in the Palace of Electricity. 
Current for all of the tests was taken from a 200 k.w., 2300 volt, 
60 cycle, three-phase generator, one phase only being used. This 
generator was mounted on the same shaft with a 200 k.w. 
direct current motor, the two machines comprising the same 
motor-generator set that was used in the rail tests of Chapter 
XII. The frequency was varied by the same general method 
employed in the tests on Rail Losses. The power was trans- 
mitted from the Bullock space in the Palace of Electricity, to 
the test tracks by means of a No. 00 B & S gage duplex cable 
which had been especially provided for this purpose by the 
American Steel and Wire Company, and installed by the Mechan- 
ical and Electrical Department of the Exposition Company. 



436 ELECTRIC RAILWAY TEST COMMISSION 

For the sixty frequency tests, the power supply was as shown 
in Fig. 112, Chapter XII. The motor-generator set was driven 
from the 500 k.w., 500 volt, 25 cycle, three-phase rotary con- 
verter, which in turn was supplied with power from the 6600 
volt, three-phase power mains of the Exposition Company; the 
pressure of these mains being reduced to the proper value by 
means of three Bullock transformers of the oil cooled type. 

For the forty frequency tests, connections were similar to 
those of Fig. 113 of Chapter XII. The motor-generator set was 
driven from a composite circuit made up of the 240 volt, direct 
current power mains in series with the 240 volt, 150 k.w. 
direct current generator; the latter being driven by the 150 
horse power, 240 volt direct current motor. This driving motor 
was supplied with power from the 240 volt direct current power 
mains. The frequency of the alternating current used in the 
tests was adjusted by means of the rheostats in the fields of the 
direct current machines. 

For the fifteen and twenty-five frequency tests the power 
supply connections were similar to those shown in Fig. 113, 
except that the field of the direct current motor, driving the 
supply alternator, was connected directly across the 240 volt 
power mains and the 240 volt direct current generator in series, 
while the armature of this motor was supplied directly from the 
240 volt power mains. By this means, the driving motor was 
supplied with a strong magnetic field, while its speed could be 
adjusted readily by means of varying the pressure across, its 
armature terminal. Power for the direct current measurements 
was furnished from the 100 k.w., 240 volt generator, and was 
transmitted to the test track by the No. 00 B & S gage, duplex 
cable above mentioned. 

The transmission cable ended at the middle of the test track. 
From this point, the power was transmitted to the east end of the 
test tracks by means of two No. 12 B & S gage rubber-covered 
wires, hung loosely from the pole brackets. In the direct cur- 
rent tests, the terminals of these wires were connected directly 
to the test track circuit through the necessary instruments. 



ALTERNATING CURRENT LOSSES IN TRACK 437 

In the alternating current tests, the terminals of these two wires 
were connected to the primaries of two Westinghouse 37^ k.w. 
transformers, having a reduction ratio of 20 to 1 or 10 to 1, as 
desired; the primaries being designed for a normal pressure of 
2200 volts, and the secondaries for 220 or 210 volts at 60 cycles 
per second. The primaries of the two transformers were con- 
nected in parallel, while the secondaries were connected in paral- 
lel or in series, according to the condition of the tests. From 
the secondaries of the transformers one lead was connected 
direct to the trolley, while the other was connected through the 
ammeter shunt and wattmeter current transformer, to the cross- 
bond connecting the two tracks at the east end of the section. 

The stretch of track tested consisted of 960 ft. of double track 
and trolley, lying between two cross-bonds from track to track. 
The direct current, supplied from the Intramural system, was 
cut off, and the west end of the track under test was short-cir- 
cuited between trolley and rails. All of the instruments were 
placed at the east end of the track. At first the measurements 
were made in the open air, but later, because of the prevailing 
low temperature, the instruments were placed in the single- 
truck car described in Chapter I, and the measurements were 
made under cover. 

WEATHER CONDITIONS. 

As the condition of the weather may seriously affect the re- 
sistance of both track and overhead, a record was kept, showing 
the temperature and moisture during the entire series of tests. 
This record, together with a general record of the tests made 
on each day, is given below. During the entire series of tests 
the weather was clear and dry, the teinperature averaging ap- 
proximately 60° Fahrenheit. 



438 



ELECTRIC RAILWAY TEST COMMISSION 



Weather Bulletin and Test Record. 



1904. 


Tests. 






Sat., Oct. 22 . . 


1- 7 inclusive 
8- 17 

Tests. 


Fair, cold, windy. 
About 45° F. 


Outside mea- 
siu"ements. 


Mon., Oct. 24 . 


20- 31 inclusive 
36- 39 

Tests. 


A.M. fair and rather 
warm. P.M. cold 
and windy. About 
65° F. 


Outside mea- 
surements. 


Tues., Oct. 25 . 


32- 35 inclusive 
40- 59 

Tests. 


A.M. wet from rain 
night before. Fair 
and windy all day. 
About 50° F. 


Measurements 
taken in car. 


Wed., Oct. 26 . 


60- 75 inclusive 
80- 83 
92- 99 " 

Tests. 


Fair day, dry weather. 
Temp, about 60° F. 


Measurements 
taken in car. 


Thurs., Oct. 27 


100-105 inclusive 
108-111 " 
114-131 " 

Tests. 


Fair day, dry weather. 
Temp, about 60° F. 


Measurements 
taken in car. 


Fri.,Oct. 28. . 


132-149 inclusive 
Tests. 


Fair day, dry weather. 
Temp, about 60°. 
Ran till noon only. 


Measurements 
taken in car. 


Sat., Oct. 29. . 


150-173 inclusive 
176-181 " 

Tests. 


Fair day, dry weather. 
Temp, about 65-70°. 


Measurements 
taken in car. 


Mon., Oct. 31 . 


174-175 inclusive 
182-211 

Tests. 


Fair day, dry weather. 
Temp, about 65°. 


Measurements 
taken in car. 


Tues. , Nov. 1 . 


211-261 inclusive 
Tests. 


Fair day, dry, smoky. 
Temp. 60°. 


Measurements 
taken in car. 


Wed., Nov. 2 . 


261-282 inclusive 


Fair day, dry. Temp. 

65° 


Measurements 
taken in car. 



ALTERNATING CURRENT LOSSES IN TRACK 439 

General Description of the Tests. 

In the preliminary tests considerable clifRculty was experi- 
enced, due to the leakage from the Intramural railroad, although 
the circuit was entirely independent. This was especially true 
when taking the fall of pressure in the track itself, in obtaining 
the direct current resistance measurements. This difficulty 
was remedied by taking out the angle-bars at both ends of the 
stretch of track imder test, thereby completely isolating it from 
the Intramural system. In doing this, joints were selected 
which had considerable air gap between the ends of the rail. 
After taking this precaution, no further difficulty with leakage 
effects was found. In order to obtain the measurements of 
the pressure drop and the total losses in track alone, a pressure 
lead was run from the west end of the track to the instruments 
at the east end. 

Six sets of observations were made, comprising 282 indepen- 
dent tests. Three sets of readings were taken for each test, 
the average being used in the final results. The current was 
varied from 50 to 600 amperes, and tests were made at fre- 
quencies of 15, 25, 40, and 60 cycles per second in each series of 
tests. The six different testing conditions were as follows: 

Series A. — This series of tests embraced those relating to 
the pressure drop and power loss in the double track and double 
trolley combined. Fig. 137 shows a diagram of connections 
used. It will be seen that the secondaries of the transformers 
were placed in parallel, one terminal being connected to the 
trolley wires, while the other terminal was connected through 
the ammeter and wattmeter, to the cross-bond between the two 
tracks. At the other end of the line, the two trolley wires and 
the four tracks were short-circuited directly by means of a No. 
0000 B. & S. gage cable connecting the cross-bond between the 
tracks to the trolley wires. 

Series B. — In these tests, the pressure drop and power loss 
on the double track alone were investigated. The connections 
were the same as those in Fig. 137, except that the pressure 



440 



ELECTRIC RAILWAY TEST COMMISSION 



across the voltmeter and the pressure coil of the wattmeter was 
the pressure drop of the track alone, instead of that of the track 
and trolley wire combined, which was the condition in Series A. 
This connection was made by means of a No. 12 J5. & >S. gage 
copper pressure wire, which was connected to the track at the 
west end of the section imder test. This pressure lead was 930 
ft. long, and was 3 ft. above the ground. 

Series C. — These tests comprised those on the single track 
and trolley combined. The connections were the same as those 
in Fig. 137, except that one trolley wire was disconnected and 



00 Trolley 




Shtmt 



Fig, 137, — Connections Used in Making the Alternating Current Tests u/ith Double Track 

and Double Trolley. 

m 

one track was isolated by cutting the cross-bonds between the 
two tracks. The tests were made on the north or upper track 
of the two. This track was selected because there were no steel 
cross-ties used in its construction, as was the case in the south 
test track. 

Series D. — This series of tests comprised those showing the 
pressure drop and power losses existing in the single track alone. 
The connections were the same as in Series B, except that the 
south track and trolley wire were disconnected as in Series C. 

Series E. — These tests comprised those showing the pres- 
sure drop and power losses occurring in the single trolley with 



ALTERNATING CURRENT LOSSES IN TRACK 441 

a single rail return. One trolley wire was disconnected, and 
three of the four rails were isolated by disconnecting the cross- 
bonding. The south rail of the north track was selected for 
these tests. One terminal of the transformer secondary was 
connected directly to the trolley wire, while the other terminal 
was connected to the rail, after passing through the ammeter 
shunt and wattmeter transformer. The circuit was closed at 
the west end by short-circuiting the trolley and rail by means 
of a No. 0000 B. & S. gage cable. The voltmeter and wattmeter 
pressure coils were connected directly across the circuit between 
the trolley and the rail at the east end of the track. 

Series F. — This series comprised the tests showing the 
pressure drop and power losses for a single rail. The connec- 
tions were similar to those of Series E, except that the voltmeter 
and the wattmeter pressure coils were connected to show the 
drop in pressure in the rail alone, instead of that of the rail and 
trolley combined. 

ORIGINAL MEASUREMENTS. 

The tests including measurements with alternating cur- 
rents, varied from 50 to 600 amperes and at frequencies 
of 15, 25, 40, 45, and 60 cycles per second. In addition, a 
large number of direct current measurements were made in 
order to determine the resistance and the losses in the var- 
ious parts of the circuit due to a direct current flowing. All 
joints made in the cables, at both ends of the track, were 
carefully tested with a low-reading voltmeter, and the resis- 
tance was found to be negligible. All cable connections were 
made with No. 0000 B. & S. gage cable, and all joints were care- 
fully made and soldered. 

In the direct current tests for resistance, a Weston milli- 
voltmeter with a shunt was used to measure the current, and 
the pressure drop was obtained by means of a second Weston 
milli-voltmeter and multiplier. 

In the alternating current tests, all currents were measured 
by means of the Stanley hot wire ammeter, used in the tests 



442 ELECTRIC RAILWAY TEST COMMISSION 

described in Chapter XII. This instrument was provided 
with two shunts, one for a full scale reading of 200 amperes, 
and the other for a full scale reading of 1000 amperes. The 
currents between 200 and 600 amperes were obtained by means 
of the 1000 ampere shunt. The alternating current pressure 
was measured by means of a Weston alternating current volt- 
meter, with a scale reading of to 75 and 150, for the higher 
values ; while a similar Weston instrument reading to 7 J and 
15 was used for the lower values of pressure. 

The alternating current power was obtained by means of a 
to 300 Thomson wattmeter and a to 150 Weston wattmeter. 
The current coils of these instruments were supplied from the 
secondary of a Westinghouse current transformer with a re- 
duction ratio from 120 to 1. The primary or heavy coil of 
this transformer was connected directly into the track circuit. 
An attempt was made to use pressure transformers on the 
voltmeter and on the pressure coil of the wattmeter, but this 
was abandoned because it was found to be unreliable, on 
account of the extremely low pressures encountered. 

A telephone connected between the test tracks and the ex- 
hibit space of the Bullock Company, was employed in taking 
the readings. The operator in the Palace of Electricity regu- 
lated the current and frequency as directed by those in charge 
of the tests at the track. Although this method was slow, it 
was possible to obtain exact values of the current and fre- 
quency, within the limits of error in the observations. Three 
sets of readings were taken for each current and frequency, the 
average being used in the final results. 

WORKING UP THE RESULTS. 

All data were carefully recorded, in preliminary tabular form, 
at the time the tests were made; the general conditions of the 
tests, the connections existing at the time the tests were made, 
and the instruments used in each case being carefully observed. 

It was of especial importance that the calibration of the in- 
struments be conducted in such a manner as to include all of 



ALTERNATING CURRENT LOSSES IN TRACK 443 

the conditions as to variations of current, pressure, and fre- 
quency, existing in the various tests. Complete cahbrations 
of this nature were made at the Bureau of Standards, immedi- 
ately at the close of the tests. All data were then worked up 
in tabular form, and the results obtained placed upon curve 
sheets for general comparison. 

It has been found to be impracticable to include the tables 
in the Report, and the graphical representation of the data is 
depended upon to show the results obtained, and the scope of 
the work undertaken. Because of the large number of tests 
made, it has been found necessary to limit the number of curve 
sheets illustrating the results of the tests contained in this 
chapter. Four curve sheets have been selected for each of the 
six series of tests which cover the investigations on the alter- 
nating current losses in track. These curve sheets show the 
variations of pressure drop per mile, the variation of watts lost 
per mile, the ratio of A.C. pressure drop to D.C. pressure drop, 
and variation of power-factor for various currents and frequen- 
cies. 

Results of the Tests. 

The results include measurements with both direct and alter- 
nating currents for each of the following six conditions: 

Series A. — Double track and double trolley. 

Series B. — Double track. 

Series C. — Single track and single trolley. 

Series D. — Single track. 

Series E. — Single rail and single trolley. 

Series F. — Single rail. 

For convenient reference and for the purposes of discussion, 
the results of the tests on track have been arranged under seven 
separate headings, ranging from Test No. 45 to Test No. 51, 
inclusive. 

Test No. 45. Direct Current. — The results o" the direct 
current tests have been used for direct comparison with the 
alternating current data, and are included in the graphical 
representation of the results obtained under the various alter- 



444 



ELECTRIC RAILWAY TEST COMMISSION 








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^ 
























^ 


^ 




















^ 


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600 Amperes 100 200 300 400 500 600Amperes 



Fig. 138, — Variation of Pressure Drop per 
Mile with'Total Amperes, Double Track and 
Trolley. 

A.C.drop 
D.C.drop 
3.6 r 



Fig. 139, — Variation of Watts Lost per Mile 
with Total Amperes, Double Track and 
Trolley, 



3. 



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30 
1<|2P 200 300 400 500 eOOAmperes 100 200 300 400 500 600Amperes 



Fig. 140, — Variation of Rates ' ' „ — - with 

D. C, Drop 

Total Amperes. Double Track and Trolley. 



Fig. 141. — Variation of Power Factor with 
Total Amperes. Double Track and Trolley. 



log 
140 



120 
100 
80 
60 
40 
20 













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60 


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100 200 300 400 500 600Amperes 




dOOAmpereaJ 



Fig. 142. — Variation of Power Drop per Mile 
with Total Amperes. Double TracL 



Fig. 143. — Variation of Watts Lost per Milq 
with Total Amperes. Double Track. 



ALTERNATING CURRENT LOSSES IN TRACK 445 



P.O. 

o o^ 

bl be 

rsrs 

dd 

8. 



Frequency 



irir:r=^- 



100 200 300 400 500 600 Amperes 




400 500 600 Amperes 



Fig. 144. — Variation of Power 



A.C. Drop 



D. C. Drop 
with Total Amperes. Double Trades. 



Fig. 145. — Variation of Power Factor with 
Total Amperes. Double Track. 
































140,000 




















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400 600 eOOAmperes 100 200 300 400 500 600Ampere3 



Fig. 146. — Variation of Pressure Drop per 
mile with Total Amperes. Single Track 
and Trolley. 



Fig. 147. — Variation of Watts lost per Mile 
with Total Amperes, Single Track and 
Trolley (north). 



























































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100 200 300 400 



Fig. 148. — Variation of the Ratios 



500 eOOAmperes 
A. C. Drop 




SOOAmperea 



with Total Amperes. 
Single Trolley. 



D. C. Drop 
Single Track and 



Fig. 149. — Variation of Power Factor with 
Total Amperes. Single Track and Single 
Trolley. 



446 ELECTRIC RAILWAY TEST COMMISSION 

nating current conditions. However, as these data are of con- 
siderable interest in themselves, they have been summarized 
and are contained in Table LXIV. While the length of track 
tested was but 916 ft. the results have been reduced to a basis 
of resistance per 1000 ft. of track in each case, as this is a more 
convenient figure for comparison. 

Table LXIV. — Direct Current Besistance of Track. — Data in Ohms Per 1000 

Feet of Track. 

Double track and double trolley 0.04749 

Double track alone 0.00545 

Single track and single trolley 0.06275 

Single track alone 0.01078 

Single rail and single trolley 0.06965 

Single rail alone 0.01885 

The Alternating Current Tests. 

Test No. 46. Double Track and Double Trolley. — 
This test includes all of the results of the measurements made 
on the double track and double trolley. The graphical repre- 
sentation of these results will be found in Figs. 138, 139, 140, and 
141. The pressure drop for various currents at given frequen- 
cies is shown in Fig. 138 and the power lost is shown in Fig. 139, 
the data for each frequency being plotted in a single curve. Fig. 
140 shows the ratios of the A.C. to the D.C. pressure drop for 
various currents at given frequencies, while Fig. 141 shows the 
variation of power-factor; the data for each frequency being 
plotted in a single curve. 

Test No. 47. Double Track Alone. — The data calcu- 
lated from the results of the investigations on the double track 
alone, are shown graphically in Figs. 142, 143, 144, and 145. 
These curves have been plotted in the same general manner as 
were those of Figs. 138, 139, 140, and 141. In all cases the cur- 
rent values have been taken as abscissas. Fig. 142 shows the 
pressure drop per mile of track for various currents at given 
frequencies. Fig. 143 shows the power losses per mile. Fig. 144 
shows the ratio of A.C. to D.C. pressure drop, and Fig. 145 shows 
the power factor. 



ALTERNATING CURRENT LOSSES IN TRACK 447 



Test No. 48. Single Track and Single Trolley. — The 
data representing the investigations on a single track and single 
trolley are shovm graphically in Figs. 146, 147, 148, and 149. 
These curves have been constructed in the same general manner 
as that employed in the construction of the curves of Figs. 138, 



^ o 




^5. 
70,000 










~ 


~ 










A 










A 


60 Freo 


UP 


icy 






/ 








60,000 






B 


*5 




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/ 


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50,000 






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40,000 






















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k 




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600 Amperes 100 200 300 400 dOO 600 Amperes 



Fig. 150. — Variation of Pressure Drop per 
Mile with Total Amperes. Single Tracf< 
Alone. 



Fig. 151. — Variation of Pressure Lost per Mile 
of Track with Total Current. Single Tracli 
Alone. 




400 600 e00Ampere8"'0 100 200 300 400 SOO 600AmpereB 
A. C. Drop ... Fig. 153. — Variation of Power Factor with 



with 



Total Current. Single Track Alone. 



Fig. 152. — Variation of o ^^^ ^^^^ 
Total Current. Single Track Alone. 

139, 140, and 141. The data showing the pressure drop per mile 
of track are given in Fig. 146, the power losses per mile are showTi 
in Fig. 147, the ratio of A.C. to D.C. pressure drop are given in 
Fig. 148, while the power factor is sho^\Ti in Fig. 149. The 
data for a given frequency are, in all cases, plotted in a single 
curve. 



448 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 49. Single Track Alone. —Figs. 150, 151, 152, 
and 153 show the results of the investigations on a single 
track alone. These curves have been constructed in the same 




^ p. 
120,000 

100,000 

<M),000 

60,000 

40,000 

20,000 



aOOAmperefi 



















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100 



300 400 SOOAmperes 



Fig. 154. — Variation of Pressure Drop with 
Total Current. Single Rail and Single 
Trolley. 



Fig. 155. — Variation of Power Lost with Total 
Current. Single Rail and Single Trolley. 




Fig. 156. — Variation of Ratio 
Single Rail and Single Track. 




500 Amperes 100 200 300 400 dOOAmceres 

C. Drop Fig. 157. — Variation of Power Factor. Single 
Rail and Single Track. 



D. C. Drop 



general manner as were the preceding ones, the data for a given 
frequency being plotted in a single curve in each case. Fig. 150 
shows the pressure drop per mile of track, Fig. 151 shows the 



I 



ALTERNATING CURRENT LOSSES IN TRACK 



449 



power losses per mile, Fig. 152 shows the ratios of the A.C. to 
D.C. pressure drop, and Fig. 153 shows the power factor. 
Test No. 50. Single Rail and Single Trolley. — The 




Fig. 158. — Variation of Pressure Drop per Mile 
with Total Current, Single Rail Alone. 



500 Amperes 



Fig. 159. — Variation of Pressure Lost per Mile 
with Total Current. Single Rail Alone. 




Fig. 160. — Variation of Ratio 



400 500 Amperes 
A. C. Drop 




500 Amperes 



D. C. Drop 



Fig. 161. — Variation of Power Factor with 
Total Current, Single Rail Atone. 



Single Rail. 

data calculated from the investigations on a single rail and a 
single trolley are graphically represented in Figs. 154, 155, 156, 
and 157. These curves are similar to those of the preceding 



450 ELECTRIC RAILWAY TEST COMMISSION 

tests. Fig. 154 shows the pressure drop per mile, Fig. 155 shows 
the power losses per mile, Fig. 156 shows the ratios of the A.C. 
to the D.C. pressure drop, and Fig. 157 shows the power factor. 
Test No. 51. Single Rail Alone. — The results of the 
investigations on a single rail alone are shown in Figs. 158, 159, 
160, and 161. These curves have been constructed in the same 
general manner as those showing the results of the preceding 
tests. Fig. 158 shows the pressure drop per mile. Fig. 159 shows 
the power losses per mile. Fig. 160 shows the ratios of the A.C. 
to D.C. pressure drop, and Fig. 161 shows the power factor. 

Discussion of Results. 

The Direct Current Tests. 

It was the desire of the Executive Committee to make an 
elaborate series of tests on the rail-bonding, which had been in- 
stalled by the American Steel and Wire Company, imder the 
direct supervision of their representative. While the time avail- 
able for making the direct and alternating current tests on the 
track did not warrant detailed tests covering the individual 
rail bonds, a sufficient number of data was obtained to form a 
very fair opinion of the value of the bonds of this track. 

•Test No. 45. Direct Currents. — The length of track 
tested was 916 ft., and the results obtained reduced to a length 
of track of 1000 ft. for the purpose of comparison, were as fol- 
lows: 

Ohms per 1000 Ft. 

Singlerail 0.01885 

Single track. 0.01078 

Double track 0.00545 

The rails of the track tested were 56-lb. rails of the A. S. C. E. 
standard, and were similar to the smaller rail used in the special 
rail tests, the results of which are shown in Chapter XII. This 
rail shows a resistance of 0.08333 ohm per mile of continuous 
rail. Reducing this value to a continuous rail length of 1000 ft. 



ALTERNATING CURRENT LOSSES IN TRACK 451 

and considering a single rail, a single continuous track, and a 
double continuous track, the following results are obtained: 

Single continuous rail . 01578 ohm 

Single continuous track . 00789 ohm 

Double continuous track . 00395 ohm 

As the bonds were all No. 00 5 & aS. gage and connected out- 
side of the angle-bars, being approximately 30 in. in length, the 
resistance of the copper of these bonds would more than offset 
the difference in resistance between the actual track and a track 
composed of continuous rail. For example, in the case of the 
single rail, there would be 33 joints every 1000 ft. The copper 
in these joints would have a resistance of 0.00650 ohm, making 
the total resistance of rails and bonds 0.02228 ohm. This 
would allow no resistance of contact between the bonds and the 
rails, and no additional conductance from the angle-bars. The 
fact that the actual resistance of the bonded track is consider- 
ably less than this value, is due to the extra conductivity offered 
by the angle-bars, and to an increase in conductivity due to the 
contact of the rail with the earth. 

The resistance results obtained for track and trolley com- 
bined, shown in Table LXIV, agree fairly well with data from 
other sources, showing the resistance in rail and trolley wire in 
a constructed line. 

Alternating Current Tests, 

The curves given in Figs. 138 to 161 inclusive, show the re- 
sults of the alternating current tests, and a study of them leads 
to some interesting deductions. 

All ciu'ves show results per mile of track. The power-factor 
curves proved to be quite irregular, and average curves (shown 
by dot and dash lines) have been drawn. 

The curves of pressure drop are nearly straight lines, particu- 
larly those for the track and trolley combined. Those for the 
track alone rise somewhat more rapidly with the larger currents, 
due to increased impedance. 



452 ELECTRIC RAILWAY TEST COMMISSION 

The power loss curves rise rapidly with increasing current, 
and the curves for alternating currents, especially at the higher 
frequencies, are much steeper than are those for direct currents. 

The curves giving the ratios of A.C. to D.C. pressure drop 
show a large increase in this ratio for the higher frequencies, 
while the power-factor curves show a decrease in the power 
factor as the frequency rises. 

In general, the magnetic properties of the steel in the rails 
determine the effects produced to a considerable extent. While 
a large part of the power loss in the rails is undoubtedly due to 
the "skin effect," hysteresis and eddy-currents have an impor- 
tant bearing on the results obtained. 

Test No. 46. Double Track and Double Trolley. — 
These tests are shown in Figs. 138, 139, 140, and 141. The pres- 
sure drop per mile for various currents and frequencies is shown 
in Fig. 183. It is seen that the pressure drop increases rapidly 
with increased frequency, and that it is considerably greater 
with a frequency of 25 cycles per second than it is with a direct 
current; while at 60 frequency the pressure drop is over three 
times that which occurs when a direct current of an equivalent 
value is flowing. 

Fig. 139 shows the power losses for various frequencies and 
currents. It is seen that while these losses become larger with 
increasing current and frequency, the increase in loss with an 
increase in frequency is not as great as the increase in pressure 
drop shown in Fig. 138. This indicates a higher inductive 
effect, and a consequent increase of the inductive component 
of the pressure drop as the frequency is increased. This is 
verified by the power-factor curves shown in Fig. 141, which 
represent the variation of power factor with current and fre- 
quency. 

The curves showing the ratios of the A.C. to the D.C. pressure 
drop are given in Fig. 140. This ratio is above three for 60 
frequency, while it is less than one and one-half for the 15 
frequency tests. Another fact to be observed in connection 
with these curves is that they all have a tendency to rise with 



ALTERNATING CURRENT LOSSES IN TRACK 453 

increasing current, while the power factor curves remain nearly 
constant. This shows a higher relative pressure drop for the 
larger currents, and indicates also a larger comparative power 
loss. Curves were also plotted showing the variation of the 
impedance with the variation in current at given frequencies. 
These curves are not included in the Report, but they indicate, 
in general, an increase in the impedance with increasing fre- 
quency, and also a slight increase in the impedance as the cm-- 
rent is increased. These results are in accordance with what 
might be expected from the discussion of the curves shown in 
Figs. 138, 139, 140, and 141. 

Test No. 47. Double Track Alone. — The results of these 
tests are shown in Figs. 142, 143, 144, and 145. The pressure 
drop per mile for various currents at given frequencies is shown 
in Fig. 142. The curves indicate a considerable increase in the 
pressure drop with increasing frequency. A comparison of 
Fig. 142 with Fig. 138 shows that a large part of the total pres- 
sure drop with the double track and double trolley, occurred in 
the overhead portion of the circuit. It is seen that the pressure 
drop at 600 amperes and 60 frequency, was 515 volts per mile for 
the double track and double trolley, w^hile it was 132 volts for the 
double track alone. This shows that but one-fourth of the total 
pressure drop occurred in the rails alone in the case of the double 
track and double trolley, for the frequency and current men- 
tioned. A comparison of the pressure drop due to a direct 
current of 600 amperes in the two cases, shows that the pressure 
drop for the double track and double trolley is 150 volts, as 
against 17 volts for the track alone. This shows a pressure 
drop of approximately nine times as much for the double track 
and double trolley as for the double track alone. From these 
data, it is seen that the increase in pressure drop with alternating 
currents is largely due to the current flowing in the rails, 
although there is an inductive effect due to the loop made by 
the trolley wire and the track. 

The losses in watts per mile for the double track are shown 
'm Fig. 143. While these losses increase rapidly both with cur- 



454 ELECTRIC RAILWAY TEST COMMISSION 

rent and frequency, it is to be observed that they do not increase 
as rapidly in proportion to the frequency as do the pressure 
drops under the same conditions. This is due to the fact that 
the inductive effect becomes greater with the increasing fre- 
quencies, and the inductive component of the pressure drop 
increases rapidly as the frequency rises. These facts are cor- 
roborated by the power factor curves which are shown in Fig. 
145. 

A study of the curves of A.C. to D.C. pressure drop, Fig. 144, 
shows an increase of this ratio with increasing frequency, and 
also the fact that this ratio is considerably higher than is the 
case with the double track and trolley combined, being fully 
twice as great for the 60 frequency tests. 

Curves showing the variation of the impedance for different 
currents and frequencies were also plotted in working up the 
results, but these have not been included in the Report. The 
impedance in general rises rapidly with increasing frequency, 
and tends to rise slightly with increasing currents. The impe- 
dance for the double track is approximately one-fourth of that 
for the double track and double trolley, and the power factor 
in general is ten per cent lower for the double track than it is 
for the double track and trolley. 

Test No. 48. Single Track and Single Trolley. — The 
results of these investigations are shown in Figs. 146, 147, 148, 
and 149. The volts drop per mile are given in Fig. 146, and 
show clearly the large increase in pressure drop with increasing 
frequency. At 500 amperes the pressure drop with a direct 
current is 155 volts; whereas it is 615 when the frequency is 
60 cycles per second. This shows an increase of 300 per cent 
in the pressure drop. 

The watts lost per mile are indicated in Fig. 147. It is seen 
that while the power losses rise rapidly with increasing current, 
there is not a very large increase in the loss with increasing 
frequency. This indicates that a considerable portion of the 
increase in pressure drop at the higher frequencies is due to 
an inductive effect; although a. part of this increase is caused 



ALTERNATING CURRENT LOSSES IN TRACK 455 

by additional power losses in the rails. An inspection of Fig. 
149 verifies the above statements, as it is seen that the power- 
factor decreases rapidly with increasing frequency. 

Fig. 148 shows the ratios of the A.C. to the D.C. pressure 
drop for various currents at given frequencies. It will be ob- 
served that the average value of this ratio at a frequency of 60 
cycles per second is approximately three and one-half times that 
for direct currents. 

In working up the results, curves were also drawn showing 
the variation of impedance with changes of current and fre- 
quency. These have not been included in the Report, but they 
show a considerable increase in impedance with increasing fre- 
quency as the frequency rises. 

Test No. 49. Single Track Alone. — The results of this 
test are shown graphically in Figs. 150, 151, 152, and 153. The 
pressure drop per mile. Fig. 150, shows a very considerable 
increase with increasing frequency. The pressure drop at 600 
amperes is 33 volts with direct current; whereas it is 350 volts 
at 60 cycles. This shows an increase in the pressure drop of 
approximately 900 per cent for this condition. A comparison 
of this curve with Fig. 146, shows that practically 50 per cent of 
the pressure drop for the single track and trolley, occurs in the 
track alone at 60 cycles and 600 amperes; whereas approxi- 
mately 17 per cent of the pressure drop for the single track and 
trolley occurs in the track alone for direct currents. This indi- 
cates that the increase in pressure drop with alternating cur- 
rents is largely due to the current flowing in the rails, although 
there is an inductive effect due to the loop formed by the trolley 
wire and the track. 

The power loss curves. Fig. 151, show an increase in the power 
lost as the frequency is raised; this increase becoming much 
more marked at the higher values of current. At 500 amperes 
the power lost due to direct current is 14,000 watts, while at 
60 frequency it is 60,000 watts, the increase being over 300 per 
cent. An inspection of Fig. 150 shows a pressure drop of 27 
volts at 500 amperes direct current, as against 258 volts at 60 



456 ELECTRIC RAILWAY TEST COMMISSION 

cycles. This is an increase of approximately 900 per cent. 
These data show that while the power lost increases rapidly 
with the frequency, it does not increase as rapidly as does the 
pressure drop. This shows an increased inductive effect in the 
rails, as the frequency rises, which fact is shown clearly in the 
power-factor curves of Fig. 153. 

A comparison of the power lost in the single track with that 
lost in the single track and single trolley combined shows that, 
for 500 amperes and 60 cycles, the loss in the track alone is 50 
per cent of the loss in the track and the trolley combined. A 
comparison of the pressure drop in these two cases at 500 am- 
peres and 60 cycles, shows that the pressure drop in the single 
track alone is 258 volts as against 610 volts for the track and 
trolley combined, the former being approximately 40 per cent 
of the latter. These results show that the power lost for the 
track alone is greater in proportion than is the pressure drop, 
indicating that the increase in power lost with increase in fre- 
quency occurs in the track itself. 

Fig. 152 shows the ratios of the A.C. to the D.C. pressure 
drop for the track alone. A comparison of these results with 
those given in Fig. 148 shows that this ratio is considerably 
higher for the track alone than it is for the track and trolley 
combined; the values of the ratio for the track alone being 
on an average twice as high as those for the track and trolley 
combined. These data bear out the statement made con- 
cerning the relative amount of power lost under the two 
conditions. 

The power-factor curves for the rail alone are given in Fig. 
153, and show the large decrease in power factor as the fre- 
quency rises. A comparison of these curves with those of Fig. 
149 shows that, in general, the power factor for the track alone 
is lower than for the track and trolley combined, especially at 
the higher frequencies. 

Curves showing the variation of impedance for different cur- 
rents at given frequencies were also plotted in working up the 
results^ but these have not been included in the Report. The 



ALTERNATING CURRENT LOSSES IN TRACK 457 

impedance in general, increases rapidly with the frequency 
and it has a tendency to rise with increasing current. 

Test No. 50. Single Rail and Single Trolley. — The 
results of these investigations are shown in Figs. 154, 155, 156, 
and 157. The volts drop per mile are given in Fig. 154, and 
show clearly a large increase in pressure drop with increasing 
frequency. At 400 amperes, the pressure drop is 147 volts 
with direct current, whereas it is 720 volts at 60 cycles per sec- 
ond. This shows an increase of more than 400 per cent in the 
pressure drop. 

The watts lost per mile are indicated in Fig. 155. It is seen 
from this curve sheet that while the power losses rise rapidly 
with increasing current, the increase of power lost with increas- 
ing frequency is not as great in proportion as is that of pres- 
sure drop. This indicates that while a considerable portion of 
the increase in pressure drop is due to an increase in the power 
loss in the rail, a portion of the increase in pressure drop is due 
to an inductive effect. 

An inspection of Fig. 157 verifies the above statements, as 
the power-factor curves show a comparatively low power-factor 
at high frequencies; the average power-factor at 60 cycles per 
second being 40 percent, and, that at 15 cycles per second being 
76 per cent. The ratios of A.C. to D.C. pressure drop are given 
in Fig. 156 and show a large increase in this ratio with increas- 
ing frequency, the average value at 60 cycles per second being 
4.7 times that for direct ciu-rents. 

In working up the results, curves were also drawn showing 
the change in impedance with variations of current at given 
frequencies. These have not been included in the Report, but 
they show a considerable increase in the impedance with in- 
creasing frequency. 

The curves all confirm the statement already made that the 
losses in the rails due to hysteresis, eddy-currents and "skin- 
effect" increase rapidly with increasing frequency. It is to be 
noted that both the power-factor and impedance curves shew 
a tendency to increase with increasing current, 



458 ELECTRIC RAILWAY TEST COMMISSION 

Test No. 51. Single Rail Alone. — The results of this 
test are shown graphically in Figs. 158, 159, 160, and 161. The 
pressure drop per mile. Fig. 158, shows a considerable increase 
with increasing frequency. The pressure drop at 400 amperes 
is 38 volts with direct current and 412 volts with alternating 
current at 60 cycles. This is an increase in the pressure drop 
of approximately 1000 per cent. A comparison of this curve 
with Fig. 154 shows that practically 60 per cent of the pressure 
drop for the single rail and trolley occurs in the rail alone at 60 
cycles and 400 amperes, whereas approximately 25 per cent of 
the pressure drop for the single rail and trolley occurs in the rail 
alone, for direct currents. An inspection of Fig. 159 shows 
that the power lost for the single rail and trolley, due to direct 
current, is 14,000 watts; while, at a frequency of 60 cycles per 
second, it is 89,000 watts at the same current, the increase 
being over 500 per cent. A comparison of this increase in the 
power lost with the corresponding increase in pressure drop, 
shows that a considerable portion of the increase in pressure drop 
was due to an inductive action in the rail itself; the power lost 
not increasing as rapidly as did the corresponding pressure drop. 

A comparison of the power lost in the single rail with that lost 
in the single rail and trolley combined, shows that, for 400 am- 
peres and 60 cycles, the loss in the track alone is 66 per cent of 
the loss in the track and trolley combined. A comparison of 
the pressure drop in these two cases, at 400 amperes and 60 
cycles, shows that the pressure drop in the single rail alone is 
approximately 57 per cent of the latter. These results show 
that the power lost for the rail alone is greater in proportion 
than is the pressure drop. This would indicate that the induc- 
tive effect of the rail and trolley combined is greater in this case 
than for the rail alone. 

This is seen to be the case from a comparison of the power 
factors for 400 amperes and 60 cycles, as shown in Figs. 157 and 
161, It is seen that the power factor is just over 45 per cent 
for the rail and trolley combined, whereas it is 54 per cent for 
the rail alone. 



ALTERNATING CURRENT LOSSES IN TRACK 459 

Fig. 160 shows the ratios of the A.C. to the D.C. pressure drop 
for the track alone. A comparison of these results with those 
given in Fig. 156 shows that this ratio is considerably higher 
for the track alo e than it is for the track and trolley combined. 
This indicates a large increase in power lost in the rail itself 
with increasing frequency, as the power factors are not materi- 
ally different in the two cases. An inspection of these curves 
shows that the values of the ratios of the rail alone are on an 
average more than twice as high as those for the rail and trolley 
combined. 

The power-factor curves, Fig. 157, show that the power factor 
decreases as the frequency rises, the average value being ap- 
proximately 65 per cent with a frequency of 15 cycles per sec- 
ond; whereas it is less than 50 per cent at 60 cycles per second. 
The power-factor curves have a general tendency to rise with 
increasing current. This shows an increased proportionate 
loss of power as the current rises. 

Curves showing a variation of impedance for different cur- 
rents and frequencies, were also plotted in working up the re- 
sults, but these had not been included in the Report. The 
impedance in general increases rapidly with the frequency, 
and there is a slight increase in its value with increasing current. 



PART VII. 
TRAIN AND AIR RESISTANCE TESTS. 



461 



CHAPTER XIV. 
TRAIN RESISTANCE TESTS OF INTERURBAN CARS. 



Objects of the Tests. 

The primary object of these tests was to secure data relating 
to the train resistance of an interurban car, operated both with 
and without a trailer, at speeds of from thirty to seventy miles 
an hour. A second object was to obtain similar data on a djna,- 
mometer car, specially constructed for the purpose of separately 
measuring the air resistance, and described in Chapter XV. It 
was also desired to obtain data for the determination of the total 
train resistance of the dynamometer car with different forms of 
front and rear vestibule. 

Synopsis of Results. 

The general results of the resistance tests are given in Table 
LXV, the data shown in condensed form in this table being 
given in more complete form in the latter part of the chapter. 

General Conditions of the Tests. 

The subject of train resistance has received considerable atten- 
tion within the past few years, owing to the fact that it is one of 
the most important problems in electric railway practice at the 
present time. Many train resistance tests have been made by 
various investigators, and a number of valuable empirical for- 
mulas have been constructed from the results of these tests. 

In planning the present series of tests, it was decided to 
make a series of investigations by a somewhat different method 
from that ordinarily used, in addition to the series of resist- 
ance tests in which the ordinary method of measuring the 

463 



464 ELECTRIC RAILWAY TEST COMMISSION 

Table LXV. — Synopsis of Results of Train Resistance Tests. 



Car Tested and 
Vestibule 

ArRANG£M£NT. 


Resistance in Lbs. per Ton at 
Various Speeds.* 


Remarks. 


20 
m.p.h. 


30 
m.p.h. 


40 
m.p.h. 


50 
m.p.h. 


60 
m.p.h. 


70 
m.p.h. 


Car 284 on Test Track 


12 
12 






15.0 
15.0 


20.0 
20.0 
20.0 
19.0 
21.0 

22.5 
19.0 
21.0 
26.0 
21.8 
22.2 
26.0 


26.8 
26.8 
26.0 
25.0 

24.8 

27.5 
23.5 
26.2 
33.8 

28.7 
28.2 
32.6 


35. Ot 
35. Ot 






running forward. 
Car 284 on Test Track 






running backward. 
Car 284 in Service 






Tests.without trailer. 
Car 284 in Service 












Tests, with trailer. 

Louisiana with para- 
bolic wedge front 
vestibule. 

Louisiana with stan- 
dard front vestibule. 

Louisiana with para- 
bolic front vestibule. 

Louisiana with stan- 
dard front vestibule. 

Louisiana with flat 


16 

17 
15 
16 
17 
14 
15 
18 


8 

5 

5 






18.2 

19.4 
16.2 
17.9 
20.2 
16.7 
17.8 
21.4 


30.0 

33.8 

30.0 

32.6 

43. Ot 

36.5 

35.0 

41. Ot 


37 

41 
37 
40 


•Ot 

•Ot 

• Ot 

• Ot 


Standard Rear Ves- 
tibule. 

Parabolic wedge 
rear vestibule. 

Standard rear vesti- 
bule. 

Parabolic rear vesti- 
bvile. 

Standard rear vesti- 


front vestibule. 
Louisiana with stan- 




bule. 
Flat rear vestibule. 


dard front vestibule. 
Louisiana with stan- 




No rear vestibule. 


dard front vestibule. 
Louisiana with no 




Standard rear vesti- 


front vestibule. 




bule. 



* These values are taken from the Resistance Curves. 
t Estimated. 

electrical input and the speed was employed. To do this re- 
quired correction for acceleration and grade, allowance being 
made also for the velocity and direction of the wind. Before 
beginning the tests a study was made of a number of the em- 
pirical formulas mentioned above, and curves for the special 
djmamometer car were constructed in accordance with the con- 
ditions of the various formulas. The results of the application 
of these formulas are given in Figs. 162, 163, and 164. 

General Description of the Tests. 

For the purpose of these tests a section of tangent track was 
selected on the "Northern" division of the Indiana Union Trac- 
tion Company's system. This track was not quite level, but a 
careful survey of the grades was made so that corrections could 
be made for the changes in speed and resistance, due to such 
grades. 



TRAIN RESISTANCE TESTS 



465 



The section of the track selected for the tests was sHghtly 
less than five miles in length, and extended from Noblesville 
southwesterly toward the town of Carmel. The direction of the 
track departed approximately 24 degrees from the east and west 
Hne. The profile is shown in Fig. 171. This track was of the 
most recent type of construction employed by the Indiana Union 
Traction Company. It consisted of 70-pound Tee rails laid on 



5000 



4500 



4000 



3500 



isooo- 



S2500 



C4 



2000 



1500 



1000 



500 




40 50 60 

Miles per Hour 

F!g. 162. — Application of Train Resistance Formulas to Car Louisiana (Results Shown in 

Pounds Pressure at Various Speeds). 

standard oak ties. It was gravel ballasted and in first-class 
condition at the time the tests were made. Certain rims were 
also selected from the data of the service tests described in 
Chapter IV. 

THE CARS TESTED. 

The cars selected for test were Car No. 284 of the Indiana 
Union Traction Company's system, fully described in Chapter 



466 



BLECmiC RAILWAY TEST COMMISSION 



1, and the special dynamometer car "Louisiana," described in 
Chapter XV. The trailer, used in some of the tests on Car No. 
284, was the one employed in the service tests described in 
Chapter IV, and was equipped and loaded as in those tests. 



SCHEDULES OF THE TESTS. 



The tests included in the present chapter comprise a series 
of thirty runs with Car No. 284, and a series of sixty-four runs 
with the car "Louisiana." 



1000 




10 20 30 40 50 60 70 80 90 100 

Fig. 163. —Application of Train Resistance Formulas to Car Louisiana (Results Shown in Kilo- 
watts Lost at Various Speeds). 

The data relating to Car No. 284 are subdivided into two gen- 
eral classes, and are considered under the headings Test No. 52 
and Test No. 53. These data were selected from a number of 
runs made on the test section of track near Noblesville, and also 
from the service runs between Muncie and Indianapolis: 



TRAIN RESISTANCE TESTS 



467 



The data relating to the car "Louisiana" are subdivided into 
four general classes, and are considered under the headings Test 
No. 54, Test No. 55, Test No. 56, and Test No. 57. These data 
have been selected from among several hundred runs made 



lUUU" 




































/ 




/ 


QOCi- 




































/ 




// 




































1 


/ 


/ 


/ 


800 










Re 


sist 


anc 


eF< 


)rm 


alas 


















/; 


/ 












Car Louisiana 


, 














/ 


/ 


7 




700 












Av. 


Wid 


:h8 
t-38 


Ton 














/ 




/ 


/ 














"W 


'eigl 


u 












/ 


/ 


// 






000 






























1 


/ 


/ 


/ 


































/ 


f/ 


/ 








■500 






























i\ 


fe 


/ 


































7 


f 


J 








/ 


400 


























/ 


/ 









,o« 


y/ 


/ 


























/ 


/, 


/ 






y 


/ 


'/ 


300 
























/ 


/ 


/ 






/' 


^ 

V 


^ 


^^ 






















/ 





/ 








X 


200 






















// 


V 




y 


/ 


-^ 


N 


^*1 


s* 




















^ 


y 




^ 


y 


i^ 


\A 


^1 


ce^^ 


?^ 


,^c 


















x; 


^ 


y 




^ 


^. 


^ 


^ 


^^ 


^.o^^ 




















^ 


^ 


[:- 








=^ 






















_^ 


^ 


^ 






^r-s= 



























10 



20 



30 



40 50 60 

Miles per Hour 



70 



80 



90 



100 



Fig. 164. —Application of Train Resistance Formulas to Car Louisiana {Results Shown in 

Horse-power Lost at Various Speeds). 

under various conditions of speed, direction, and arrangement 
of vestibules and car body. The results are used both for the 
study of car resistance as a whole in the present chapter, and for 
the independent study of air resistance on vestibules and car 
bodies in Chapter XVI. 

Tests No 52, Car No. 284. —The following twenty runs 
made with Car No. 284 include those carried out on the special 
test track between Carmel and Nobles ville. 



I 



468 



J^LECTRtC RAILWAY TEST COMMISSION 



Schedule of Buns for Test No. 52. Besistance Buns with Car 
No. 284, on Test Track. 



Run. 



A 

B 

C 

D 

E 

F 

G 

H 

I 

J. 

K 

L 

M 

N 

O 

P 

Q 
R 

S 
T 



Date, 
1905. 



Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 
Feb. 6 



Car 


Car 


Going. 


Pointed. 


Fast 


East 


East 


East 


West 


West 


East 


East 


East 


East 


AVest 


West 


West 


West 


East 


East 


West 


West 


West 


West 


West 


East 


West 


East 


West 


East 


East 


West 


East 


West 


East 


West 


West 


East 


West 


East 


East 


West 


East 


West 



Motor Connections. 



4 motors in parallel 

2 motors in parallel 

4 motors in parallel 

2 motors in parallel 

4 motors in series-parallel 

2 motors in parallel 

2 motors in parallel 

2 motors in series 

4 motors in series-parallel 

2 motors in series 

4 motors in parallel 

2 motors in parallel 

2 motors in parallel 

4 motors in parallel 

2 motors in parallel 

2 motors ri parallel 

4 motors in series-parallel 

2 motors in series 

4 motors in series-parallel 

2 motors in series 



Test No. 53, Car No. 284. — The following ten runs are taken 
from the service runs of Car No. 284 described in Chapter IV, 
and were specially selected for a study of train resistance. 

Schedule of Buns for Test No. 53. Besistance Buns Selected 

From Service Tests. 



Run. 


Date, 
1905. 


From 
Pole No. 


To Pole 
No. 


Remarks. 


A 


Feb. 4 
Feb. 3 
Feb. 3 
Feb. 3 
Feb. 3 
Feb. 3 
Feb. 4 
Feb. 4 
Feb. 4 
Feb. 4 


820 

820 

500 

1260 

2100 

1465 

820 

1260 

2100 

1465 


670 

670 

595 

1465 

1950 

1260 

675 

1465 

1950 

1265 


Without trailer 


B 


Without trailer 


C 


Without trailer 


D 


Without trailer 


E 


Without trailer 


F 


Without trailer 


G 


With trailer 


H 


With trailer 


I 


With trailer 


J 


With trailer 







Test No. 54, Car " Louisiana." — The following sixteen runs 
were selected from over one hundred runs made with the " para- 
bolic-wedge" shaped movable vestibule and the standard fixed 
vestibule in position. 



TRAIN RESISTANCE TESTS 



469 



Schedule of Runs for Test No. 54- Resistance Runs with 
Paraholic-Wedge Vestibule. 



Run, 




A 
B 

C 
D 
E 
F 
G 
H 
I 

J. 
K 
L 
M 

N 
O 
P 



Feb. 20 
Feb. 20 

Feb. 16 
Feb. 18 
Feb. 16 
Feb. 11 
Feb. 17 
Feb. 17 
Feb. 20 

Feb. 20 
Feb. 17 
Feb. 17 
Feb. 16 
Feb. 17 
Feb. 16 
Feb. 16 



Car 


Car 


Going. 


Pointed. 


East 


East 


West 


West 


East 


East 


West 


West 


East 


East 


East 


East 


West 


West 


West 


West 


East 


West 


West 


East 


East 


West 


East 


West 


West 


East 


East 


West 


West 


East 


West 


East 



Motor Connections. 



4 motors iii parallel 

4 motors in parallel, 4 grids 
on motors 

2 motors in parallel 

4 motors in parallel 

4 motors in series-parallel 

2 motors in series 

4 motors in series-parallel 

2 motors in series 

4 motors in parallel, 16 sec- 
tions of grids on motors 

4 motors in parallel 

4 motors in parallel 

4 motors in series-parallel 

2 motors in parallel 

2 motors in series 

2 motors in series 

2 motors in series. 



Test No. 55, Car "Louisiana." — The following sixteen runs 
were selected from forty runs made with the " parabolic " shaped 
movable vestibule and the standard fixed vestibule in position. 



Schedule of Runs for Test No. 55. Runs With Parabolic Vestibule. 



Run. 



A 

B 

C 

D 
E 
F 
G 
H 



Date, 
1905. 



Feb. 21 

Feb. 21 

Feb. 22 

Feb. 22 
Feb. 22 
Feb. 22 
Feb. 22 
Feb. 22 



Car 
Going. 


Car 
Pointed. 


East 


East 


West 


West 


West 


East 


East 
West 
East 
West 
West 


East 
West 
East 
West 
West 



Motor Connections. 



4 motors in parallel, 4 sec- 
tions of grids on motors 

4 motors in parallel, 4 sec- 
tions of grids on motors 

2 motors in parallel, no grids 
on motors 

4 motors in series 

2 motors in parallel 

2 motors in series 

4 motors in series 

2 motors in series 



4:70 



ELECTRIC RAILWAY TEST COMMISSION 



Schedule of Runs for Test No. 55 — Continued. 



Run. 



I 

J. 

K 
L 

M 

N 
O 
P 



Date, 
1905. 



Feb. 21 

Feb. 21 

Feb. 22 
Feb. 22 

Feb. 22 
Feb. 22 
Feb. 22 
Feb. 22 



Car 


Car 


Going. 


Pointed. 


East 


West 


West 


East 


East 


West 


West 


East 


East 


West 


" East 


West 


West 


East 


West 


East 



Motor Connections. 



4 motors in parallel, 4 sec- 
tions of grids on motors 

4 motors in parallel, 4 sec- 
tions of grids on motors 

2 motors in parallel 

2 motors in parallel, no grids 
on motors 

4 motors in series 

2 motors in series 

4 motors in series-parallel 

2 motors in series 



Test No. 56, Car "Louisiana." — The following sixteen runs 
were selected from thirty-six runs made with the " flat " movable 
vestibule and the standard fixed vestibule in position. 



Schedule of Runs for Test No. 56. Runs With Flat Vestibule. 



Run. 



A 

B 

C 
D 
E 
F 
G 
H 
I 

J. 

K 
L 
M 

N 
O 
P 



Date, 
1905. 



Feb. 28 

Feb. 28 

Feb. 25 
Feb. 27 
Feb. 27 
Feb. 27 
Feb. 27 
Feb. 27 
Feb. 28 

Feb. 28 

Feb. 27 
Feb. 27 
Feb. 25 
Feb. 27 
Feb. 27 
Feb. 27 



Car 
Going. 



East 

West 

East 

East 

West 

West 

East 

West 

East 

West 



Car 
Pointed. 



East 

West 

East 

East 

West 

West 

East 

West 

West 

East 



East 


West 


East 


West 


West 


East 


East 


West 


West 


East 


West 


East 



Motor Connections. 



4 motors in parallel, 4 sec- 
tions of grids on motors 

4 motors in parallel, 24 sec- 
tions of grids on motors 

4 motors in parallel 

4 motors in series-parallel 

2 motors in parallel 

4 motors in series-parallel 

2 motors in series 

2 motors in series 

4 motors in parallel, 4 sec- 
tions of grids on motors 

4 motors in parallel, 4 sec- 
tions of grids on motors 

2 motors in parallel 

4 motors in series-parallel 

2 motors in parallel 

2 motors in series 

4 motors in series-parallel 

2 motors in series 



TRAIN RESISTANCE TESTS 



471 



Test No. 57, Car " Louisiana." — The following sixteen runs 
were selected from thirty-eight runs made with the "standard" 
movable vestibule in position, no vestibule being attached to 
the other end of the car body. 



Schedule of Buns for Test No. 57. Runs With Standard Vestibule. 



Run. 



A 

B 

C 
D 
E 
F 
G 
H 
I 

J. 

K 
L 

M 
N 
O 
P 



Date, 
1905. 



Mar. 10 

Mar. 10 

Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 
Mar. 10 

Mar. 10 

Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 
Mar. 7 



Car 


Car 


Going. 


Pointed. 


East 


East 


West 


West 


East 


East 


East 


East 


West 


West 


East 


East 


West 


West 


West 


West 


East 


West 


West 


East 


East 


West 


West 


East 


West 


East 


East 


West 


East 


West 


West 


East 



Motor Connections. 



4 motors in parallel, 20 sec- 
tions of grids on motors 

4 motors in parallel, 12 sec- 
tions of grids on motors 

2 motors in parallel 

4 motors in series-parallel 

2 motors in parallel 

2 motors in series 

4 motors in series-parallel 

2 motors in series 

4 motors in parallel, 8 sec- 
tions of grids on motors 

4 motors in parallel, 16 sec- 
tions of grids on motors 

2 motors in parallel 

2 motors in parallel 

4 motors in series-parallel 

4 motors lq series-parallel 

2 motors in series 

2 motors in series 



GENERAL METHOD EMPLOYED. 

The general plan followed in making all of these tests was to 
allow the car to attain a practically constant speed before begin- 
ning to record data. All the readings were then taken over the 
desired section of track and the observations were stopped 
before the brakes were applied. Finally, in working up the 
results, a section from each run was selected in which the con- 
ditions were as nearly uniform as possible. 



ORIGINAL MEASUREMENTS. 

The measurements made during the tests consisted simply 
of accurate speed determinations and electrical input measure- 



472 ELECTRIC RAILWAY TEST COMMISSION 

ments. Wind and temperature data were also included, in 
order to allow for the effect of atmospheric conditions. 

Speed Measurements. 

Both cars were equipped with a simple speed generator geared 
by means of sprockets and chain to the car axle, as already de- 
scribed and illustrated in Chapter IV. Car No. 284 was equipped 
with the elaborate recording apparatus, also described and illus- 
trated in Chapter IV, and which included a device for tracing 
a speed curve on the record strip. The speed was checked by 
recording on the chronograph record the time of passing particu- 
lar poles, each ten poles or less being marked on the record. At 
high speeds every ten poles were marked, at lower speeds every 
five poles, and at very low speeds the position of each pole was 
indicated. 

On the "Louisiana" no graphical record of speed was made, 
but the indications of the speed voltmeter were recorded every 
five seconds. A chronograph pole record was also kept, similar 
to that in the tests of Car No. 284. 

Electrical Measurements. 

The electrical measurements comprised those of current and 
e.m.f. The current records from the tests of Car 284 were 
made by the automatic apparatus already described, and by 
the recording ammeter of the General Electric Company. These 
two devices formed an accurate check upon each other. E.m.f. 
was recorded graphically as in all other tests. On the "Louisi- 
ana," only the General Electric recording ammeter was em- 
ployed, but a Weston indicating anmieter was read frequently 
in order to check the graphical record. The e.m.f. was re- 
corded at five-second intervals. No attempt was made to meas- 
ure directly the power in these tests, as it was considered to be 
more advisable to make the tests of current and e.m.f. with 
the greatest accuracy and to depend upon the product of the 
averages of these quantities for the power readings. As the 
current and e.m.f. were substantially constant in the tests, 
their product accurately gave the average power. 



TRAIN RESISTANCE TESTS 473 

WORKING UP THE RESULTS. 

Electrical Data. 

In all of the tests the readings of e.m.f. were averaged from 
the graphical records, or from the records made periodically, 
and corrected for errors in the instruments. The current rec- 
ords were integrated for the period selected for the tests, these 
results being compared with the periodical measurements. 

From these data the power was obtained by multiplying 
together the average e.m.f. and the average current for the 
period of the test. The electrical power delivered by the motors 
to the car axles was obtained by reference to the efficiency curves 
of the motors. 

Speed Data. 

The first step in preparing the speed data was to obtain ac- 
curate calibrations of the speed indicating device. This was 
done by running the car both forward and backward at vari- 
ous speeds and by checking the indications of the speed device 
by the actual speed as shown by the distance traversed in a 
given time. The results of these cahbrations were plotted in 
the form of curves. The readings obtained during the tests 
were then averaged and corrected by reference to these curves. 

The next step was to dbtain, from the graphical record, 
the exact location by poles of the start and the stop of each 
test and the time interval corresponding thereto. The aver- 
age speed was then calculated from the time-distance data thus 
obtained. These data were considered to be more reliable than 
those furnished by the speed voltmeter, and where they differed 
the voltmeter readings were corrected to correspond with the 
distance and time. As distance and time measurements are 
the simplest of all measurements to make,, and as they were 
made with great accuracy in these tests, they were considered 
to be the final data of reference for average speed. It would 
not have been possible, however, to have conducted the tests 
satisfactorily without the speed generator, for the reason that 



474 ELECTRIC RAILWAY TEST COMMISSION 

the latter gave direct and quick indications of the variation of 
the speed and therefore data for calculating the acceleration. 
It should be said, however, that the two methods of measuring 
speed gave nearly similar results ; in some cases being absolutely 
the same, and in others differing by but a few per cent. 

Acceleration and Grade Data. 

While the attempt was made in every test to maintain the 
speed at a imiform value, it was not always possible to do this 
because of the grades, especially in the runs at the high speeds. 
As the acceleration diminishes with increasing speed, the tests 
at 60 miles an hour and upward required several miles of run- 
ning before a uniform speed was reached. 

In correcting for acceleration, the records obtained by the 
speed indicating device were considered to give accurately the 
relative speed at start and stop. The average speed from these 
records was compared with the average speed from the time- 
distance measurements, and the former were corrected to con- 
form to the latter. The speed at the start of the tests was sub- 
tracted from that at the stop, and this was divided by the total 
time interval in seconds, the result giving the acceleration in 
miles per hour per second. 

In allowing for the grades, the elevations of the poles at the 
start and the stop of the test were determined from the profile. 
The net grade for the runs was then obtained by dividing the 
difference in elevation by the distance between these poles. In 
working up the results, the algebraic sum of the errors due to 
grade and acceleration was obtained, and this correction was 
made in the results obtained from the electrical measurements. 

Determination of the Horizontal Effort. 
In all cases, the horizontal effort was determined directly 
from the electrical power input. The loss in the motors was 
determined from their efficiency curves, due allowance being 
made for the variation of efficiency with the e.m.f. at the motor 
terminals. The power output of the motors was then reduced 



TRAIN RESISTANCE TESTS 475 

to its mechanical equivalent in foot-pounds per minute, and 
this was divided by the average velocity in feet per minute, 
giving, as a result, the total horizontal effort uncorrected for 
acceleration and grade. This was reduced to pounds per ton 
before applying the curves. 

In correcting for acceleration, the difference in speed between 
start and stop was divided by the total interval of the run in 
seconds, and this quantity was reduced to terms of feet per 
second per second. The mass corresponding to one ton, that is, 
2000 lbs., divided by 32.2 (the acceleration due to gravity), was 
then multiplied by the average acceleration, giving the correc- 
tion in pounds per ton. 

In a similar manner, the correction for grade was made, the 
net correction for the combined effect of grade and acceleration 
being applied to the gross value already mentioned. 

Plotting the Curves. 
In plotting the groups of resistance curves, the individual 
curves were first plotted in accordance with the various points 
determined experimentally. The curves were then superim- 
posed upon each other with the idea of determining the char- 
acteristic form of the group. Each individual curve of the group 
was then modified to conform to the general shape for the group, 
and by this means each curve represents an accuracy equal to 
the average of all of the curves for the group. 

Results of the Tests. 

For the purpose of study the results are arranged in Tables 
LXVI to LXXI, giving the data for various combinations. 
From these data the resistance curves of Figs. 166 to 170, inclu- 
sive, were produced. 

As the points from which the various curves were plotted 
show considerable variation in location, all of these original 
points have been plotted. The tables, taken in connection with 
the description of the method of working up the results, are 
self-explanatory. 



476 



ELECTRIC RAILWAY TEST COMMISSION 



The results show the comparative performance of two inter- 
urban cars similarly equipped, the one being a standard car and 
the other a special car constructed for measurements of air 
resistance. These cars were of nearly the same weight, the 
standard car, however, exposing somewhat less surface to the 
action of the air. 

Test No. 52, Car No. 284. — Table LXVI and Fig. 166 cover 
the results of a series of 20 special runs made with the inter- 
urban car No. 284 on the tangent test track. 































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F'lg. 166. — Resistance Curves, Test No. 52. 



Car No. 284. 



Test No. 53, Car No. 284. — Table LXVII shows similar data 
for the same car operating under regular service conditions with 
and without a trailer. No curves have been plotted from the 
results shown in this table, as the data do not cover a sufficiently 
wide range of variation. 

Test No. 54, Car "Louisiana.'^— Table LXVIII and Fig. 167 
give the data resulting from tests on the Car " Louisiana " when 
equipped with the parabolic wedge-shaped vestibule, the first 
half of the Table (runs A to H) giving the results with the car 
running forward in both directions on the track, while runs I to 
P show the results with the car running backward, 



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TRAIN RESISTANCE TESTS 



479 



Test No. 55, Car "Louisiana." —Table LXIX and Fig. 168 
show the data for the ''Louisiana" equipped with the parabolic 
vestibule. Runs A to H give the results for the car running 
forward, while runs I to P show the results with the car running 
backward. 



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F\g. 167.— Resistance Curves, Test No. 54. Car Louisiana with Parabolic Wedge and Standard 

Vestibules. 



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Fig. 168. — Resistance Curves, Test No. 58. Car Louisiana with Parabolic and Standard Vesti- 
bule. 

Test No. 56, Car "Louisiana."— Table LXX and Fig. 169 
show the data for the '' Louisiana " equipped with the flat vesti- 
bule. Runs A to H give the results for the car running forward, 
while runs I to P show the results with the car running back- 
ward. 



480 



ELECTRIC RAILWAY TEST COMMISSION 



Test No. 57, Car "Louisiana." — Table LXXI and Fig. 170 
give the results of the tests on the " Louisiana " equipped with 
the standard vestibule. Runs A to H are for the car running 
forward, while runs I to P are for backward operation. 




30 



50 



60 



40 
Miles per Hour 

Fig. 169. —Resistance Curves, Test No. 56. Car Louisiana iiitfi Flat and Standard Vestibule. 





























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Rear Vestibule. 



TRAIN RESISTANCE TESTS 



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TRAIN RESISTANCE TESTS 485 

In all of the tests on the " Louisiana/' excepting Test No. 57, 
the standard vestibule is on the rear, and in Test No. 57 there 
was no rear vestibule. 

Discussion of Results. 

The effect of variation in the speed of an interurban car on 
the resistance is clearly brought out in the tables and curves 
comprised in this chapter. A comparison of these data with 
the curves of Figs. 162, 163, and 164 given at the beginning of 
the chapter, shows that both Car No. 284 and the "Louisiana" 
exhibited a train resistance intermediate between the extremes 
of the theoretical curves. 

Car No. 284 shows an average resistance between 30 and 60 
miles an hour of 25 lbs. per ton, varying between the extreme 
of 15 lbs. at 30 miles an hour and 35 lbs. per ton at 60 miles per 
hour. These figures conform closely with the average results 
of tests given by previous experimenters in this line of work. 
The data show what resistance may be expected on a level track 
and under ordinary conditions of service. Taken together with 
the tests on the " Louisiana," a sufficient variety of weather con- 
ditions was encountered to permit of the elimination of the 
effect of wind upon the car resistance. 

The data furnished by the "Louisiana" tests are the most 
important, in that they show the effect of a change of form of 
the vestibule upon the resistance, and hence exhibit in a marked 
manner the extent of the influence of the air resistance upon the 
total resistance. In most of the formulas covering train resist- 
ance, the air component is assumed to vary with the square of 
the speed. The fact that there is a considerable variation in 
the resistance with the speed, is evidence of the increasing influ- 
ence of this resistance at high speeds; for the mechanical resist- 
ance, aside from the resistance of the air, does not vary greatly 
with the speed. 

While it is not to be expected that the points from which 
resistance curves are plotted will all lie on smooth curves, on 
account of the difficulty of making exact determinations, never- 



48G ELECTRIC RAILWAY TEST COMMISSION 

theless, all of the curves show a consistent tendency toward well 
defined curves. The irregularity of the points is due also to the 
fact that a car does not exhibit the same resistance on two suc- 
cessive runs under exactly the same general conditions, as there 
are variables affecting the result which are not measurable, and 
which are not under the control of the experimenter. 

Such variables are the resistance between the wheel flange 
and the rails, the instantaneous variation in direction and veloc- 
ity of the wind, instantaneous variations in grade and accelera- 
tion, and changes in lubrication of the various bearings and 
gears forming parts of the equipment. It is well known that 
the losses in bearings and in gears can be determined only ap- 
proximately, and variations of several per cent in these losses 
may be expected in the same equipment. With these indeter- 
minate variables, should be included the change in the effi- 
ciency of the motors due to fluctuations in the line pressure. 
The line pressure is constantly varying in a test, and the result- 
ant changes in motor efficiency can only be accoimted for in a 
general way in calculating the train resistance. 

These facts are clearly borne out in the tests discussed in this 
chapter from the fact that, while each measurement was made 
with extreme care and with substantial accuracy, there is a 
variation in the results which can only be accounted for through 
the uncertain elements mentioned. However, the curves of 
resistance which have been determined are sufficiently nimier- 
ous, and the resistance constants are so consistent, especially 
at the higher speeds, that it is safe to make a number of deduc- 
tions therefrom. 

As would be expected, the greatest resistance at speeds of 
from 40 to 60 miles an hour, is obtained when a flat vestibule 
is used. The increase of resistance of the flat vestibule over 
other forms is from 20 to 40 per cent at a speed of 60 miles an 
hour. At speeds below 40 miles an hour, the flat vestibule does 
not show any great increase in resistance over other forms. 
The tests with the car equipped with the flat vestibule show also, 
as would be expected, that the train resistance is considerably 



TRAIN RESISTANCE TESTS 487 

greater when the car is running forward than it is when the car 
is running backward. This difference is practically the same 
when the car is equipped with the standard vestibule in front. 
In both of these cases, there is a considerable suction in the rear 
when the car is running forw^ard. That this is true is further 
evidenced by a study of runs I to P in Table LXXI, in w^hich 
tests the standard vestibule was on the front and no vestibule 
on the rear; that is, the rear was perfectly flat. In this case, 
the resistance with the car running backw^ard was very much 
greater than with the same car running forward, and the figures 
conform very closely with the corresponding data of Table LXX, 
in which tests the car w^as equipped with the flat vestibule. 
This shows clearly that it is not sufficient to have a well-formed 
front vestibule, but that the rear vestibule also requires atten- 
tion. 

A comparison of Tables LXVIII, LXIX, and LXX, in which 
the car is equipped with the parabolic wedge, parabolic and 
standard vestibules, respectively, shows several interesting and 
practical features. In the first place, as w^ould be expected, the 
total resistance does not vary greatly with the form of the vesti- 
bule. The reason for this is that the variation of vestibule form 
does not produce a sufficient effect on the total resistance to be 
very noticeable, excepting in cases where there is great diver- 
gence in form. It w^ould be expected that the parabolic wedge 
would offer a much smaller resistance, but the difference between 
this and the parabolic form is not great enough to produce any 
marked effect on the total resistance. It must be left to the 
special tests, considered in Chapter XVI, to determine the exact 
effect of each of these forms upon the total resistance. 



CHAPTER XV. 
THE TEST CAR " LOUISIANA." 



Introduction. 



The " Louisiana " is an especially designed dynamometer car 
which was constructed for the purpose of determining the 
effect of the air pressure upon the front, the sides, and the rear 
of a car when running on a tangent level track at various speeds 
up to 70 miles an hour. 

Various forms of movable vestibules were designed and con- 
structed so that the investigations not only permitted of a deter- 
mination of the effect of the shape of vestibule, but also a 
complete separation of the vestibule pressure from the 
total car body pressure. As the total power required to 
drive the car was obtained from the electrical input data, a 
separation of the total power into its various component parts 
was also possible. 

The results of the air resistance tests are given in Chapter 
XVI, the present chapter being devoted to a more or less de- 
tailed description of the car itself. 

General Considerations Involved. 

The particular purpose of the air resistance tests was to meas- 
ure the air components of the car resistance independently of 
the total resistance. Apparently, the only direct method of 
accomplishing this was to suspend the car body above the trucks 
in such a way that the air pressure upon the car body could be 
measured by suitable dynamometers. Further, as it was de- 
sired to separate the head resistance and the rear resistance from 
the total air resistance, the natural plan was to suspend the ves- 



THE TEST CAR ''LOUISIANA" 489 

tibule separate from the body and to provide a suitable dyna- 
mometer for measuring the force exerted against the body by 
the vestibule. While this involved numerous difficulties, they 
were finally overcome by practical and safe expedients. 

It was essential that the car body be entirely free from the 
driving trucks, except for the contacts through the supports, 
which contacts were made as free from friction as possible. It 
became necessary, therefore, to mount the controllers, braking ap- 
paratus, and trolley base entirely independent of the car body. 
The details of the mechanism for securing these results are given 
later in the chapter. 

In choosing a frictionless support for the car body a number 
of plans were given careful consideration. Among these 
were various knife-edged supports and various forms of 
ball and roller bearings. In view of all the circumstances, 
the double-ball bearings manufactured by the Chapman 
Ball Bearing Company were selected as the most practical for the 
purpose of the Commission. While the actual plan employed 
combined a number of most important features for safety and 
convenience, it is probable that a spring hinge would have been 
devised, if time had permitted. 

The difficult problem in connection with the designing of the 
car was that of the dynamometer for measuring the tractive 
effort exerted by the driving trucks on the car body, as well as 
that of the vestibule. An oil dynamometer with a piston rotat- 
ing to eliminate friction, would probably have been found to be 
the ideal arrangement. However, the time at the disposal of 
the Commission did not permit of the construction of such a 
dynamometer, and of making the experiments necessary to per- 
fect it. It was decided, therefore, that the simplest and most 
direct means must be employed, and for that reason a plan in- 
volving the use of levers and weighing beams was adopted. 
The firm of Fairbanks, Morse & Company manifested great 
interest in the experiments and cooperated with the Executive 
Committee in the construction of the necessary apparatus. 



490 ELECTRIC RAILWAY TEST COMMISSION 

General Conditions of the Test. 

Soon after the Executive Committee of the Electric Railway 
Test Commission began its investigations, the Indiana Union 
Traction Company placed at the disposal of the Commission, 
a section of track on the "Northern Division/' which is for sev- 
eral miles perfectly straight and well adapted to the purposes 
of making car resistance tests. This stretch of track has already 
been described in connection with the car resistance tests covered 
in Chapter XIV. 

The section employed in the present series of tests was located 
between poles numbers 10,670 and 10,920, a total length of 25,000 
ft. or nearly five miles. The section was supplied with power 
from the Noblesville substation, which was located a short dis- 
tance from the northern end of the section. This substation 
h located 42.1 miles from the power house at Anderson, from 
which it receives power over a three-phase transmission line 
at 30,000 volts. The station contains four 175 kilowatt "step 
down" transformers and two 250 kilowatt rotary converters. 
It also contains a storage battery which has a rated capacity 
of 80 amperes discharge for eight hours. In making the very 
high speed runs, the pressure on the line was increased by rais- 
ing the pressure on the generators at Anderson by means of an 
increase in their field excitation. The battery was disconnected 
from the line during the runs made at abnormally high pres- 
sure. 

The profile showing the original grades is given in Fig. 
171. As the proposed tests required an accurate knowledge 
of the profile of the track, a special survey was made to 
determine the exact grade for each one hundred feet through- 
out the test section. A portion of the track showing the original 
grades, as well as those obtained from the special survey, is 
given in Fig. 171A, while Table LXXII shows the results of the 
special survey for the entire test section. Although the poles 
were found to be spaced with great uniformity, the distances 
between the poles along the line were carefully checked, as the 



THE TEST CAR ['LOUISIANA" 491 

location of the car with reference to the poles was used in check- 
ing the calculations of the speed. The test track was divided 
into 500 ft. sections, each of which was plainly marked by a 
white sign-board approximately one foot by three, with the sec- 
tion numbsr plainly marked on both sides with figures 5 in. 
in height. These signs were placed at a height of 5 ft. above 
the car floor, so that they were on the eye level of the observer, 
' whose duty it was to record the time of passing each sign-board. 

General Description of the Dynamometer Car. 

Before entering upon the details relating to the design of con- 
struction of the '' Louisiana," the following general items will 
serve as an introduction to this description: 

The essential feature was a car body specially constructed 
by the J. G. Brill Company. This was an interurban car body 
32 ft. long, exclusive of vestibules, arranged to roll freely upon 
rails secured to the floor of a "Pressed Steel" flat car of 100,000 
lbs. capacity. In addition to this car body, a special steel vesti- 
bule and a standard vestibule were also designed and supplied by 
the J. G. Brill Company for the use of the Commission. 

Under the side sills of the dynamometer car body were 
mounted eight Chapman double-ball bearings, and these car- 
ried four axles 3tV in. in diameter and 9 ft. long. Upon the 
axles were pressed specially chilled wheels, 12 in. in diameter, 
with ground treads. The rails were also ground perfectly 
smooth where they came in contact with the wheels. By this 
method of mounting, there was comparatively little friction 
between the body and the flat car. The body was restrained 
from excessive motion by various effective safety devices. 

The pressure of the air upon the body was measured by means 
of scale beams constructed for the tests by Fairbanks, Morse 
& Company, and loaned by them to the Executive Committee. 
The beams were supplied with dash-pots, and the weighing 
mechanism consisted of the regular beam, with weights and poise ; 
and, in addition, a spring balance with a dial was attached to 



492 



ELECTRIC RAILWAY TEST COMMISSION 



Eleva + lon in Feet. 




Fig. 171.— Section of Test Tmci< between Noblesville and Carmel, Shnwina both the Original 
Grades and the Actual Grades as Obtained from the Special Survey, 



I 



THE TEST CAR "LOUISIANA" 



493 



the end of the beam to render easier the manipulation of the 
weighing mechanism. 

As safety was a most important element in these tests, two 
safety locks were constructed for the purpose of rigidly clamp- 
ing the car body to the flat car floor at all times when measure- 
ments were not being made. These locks also served to restrain 
the motion of the car body to the few inches necessary to permit 
of taking readings during the time the pressure measurements 
were being made. One of these locks also served as the point 
of attachment to the flat car of the dynamometer employed in 
measuring the air pressure on the car body. 




785 780 775 

Pole Numbers 



Fig. 171 A. — Profile of Test Tracks between Noblesville and Carmel. Indiana Union Traction Co. 



A heavy counterweight mounted on a steel lever was used to 
hold the car body against the knife edges of the lever system 
at all times, so that the dynamometer equipment (which read 
in one direction only) could be used for making measurements 
with the car going in either direction. 

In order to absorb the vibrations between the car body and 
the flat car upon which it rolled, a pair of air brake cylinders 
was mounted on the car body floor, one just forward and the 
other just back of the center of the car, the arrangement hieing 
such that their pistons pressed against the trolley post which 
was a part of the flat car. The cylinders were filled with oil, and 
were connected by means of a by-pass containing a valve 
so that the rate of flow of oil between the cylinders could 
be regulated, and the vibration absorbed to any desired 
extent. 



494 



ELECTRIC RAILWAY TEST COMMISSION 




3 



<N 



•2* 



THE TEST CAR ''LOUISIANA" 



495 



Table LXXII. 



Table of Grades between Siding 105 and Siding 109. 
Indiana Union Traction Co. 



Note. — Plus sign (+ ) indicates up grade going east. 



7f s 


^t' Cent 
-^^- Grade 


"*''• Grade 


^'^- Grade 


^^^- Grade 


Pole 
No. ^ 


Per 

Cent 


Pole ^Z 
>T„ tent 

^«- Grade 


^«- Grade 


rade 


660 




4 


8 1.04 


2 .45 


6 1.01 


830 


.74 


4 .15 


+ 1 


.07 


. .0 


-1.06 


+ .87 


- .98 


— 


.76 


- .25 


1 1 


01 


5 .03 


9 1 07 


3 .78 


7 .97 


1 


.77 


5 .29 


+ 


.95 


+ .06 


-1.08 


+ .69 


— .96 


— 


.79 


— .33 


2 


.95 


6 .10 


730 1.01 


4 .53 


8 .98 


2 


80 


6 .41 


+ 


.95 


+ .14 


— .95 


+ .37 


— 1.00 


— 


.81 


- .48 


3 1 


.02 


7 .15 


1 .99 


5 .44 


9 1.03 


3 


.82 


7 .59 


+ 1 


.09 


+ .17 


-1.03 


4- .52 


-LOG 


— 


.84 


- .70 


4 1 


.07 


8 .22 


2 1.01 


6 .47 


800 1 . 03 


4 


.82 


8 .73 


+ 1 


.06 


+ .28 


- .99 


+ .42 


— 1.00 


— 


.80 


- .77 


5 1 


05 


9 .33 


3 1.01 


7 .44 


1 95 


5 


.81 


9 .82 


+ 1 


.04 


+ .39 


— 1.04 


+ .47 


— .89 


— 


.82 


- .88 


6 


.93 


700 . 38 


4 1 02 


8 .47 


2 .99 


6 


.85 


870 . 88 


+ 


.93 


+ .37 


— 1.00 


+ .47 


-1.09 


— 


.88 


- .88 


7 


.98 


1 .39 


5 .97 


9 .45 


3 1.00 


7 


.86 


1 .96 


+ 1 


.04 


+ .42 


- .94 


+ .44 


- .92 


— 


.84 


— 1.05 


8 1 


01 


2 .39 


6 .96 


770 .40 


4 .97 


8 


.80 


2 1.00 


+ 


.98 


+ .37 


- .99 


+ .36 


— 1.03 


— 


.77 


— .94 


9 


.98 


3 .41 


7 1.01 


1 .23 


5 .96 


9 


.82 


3 .93 


+ 


.99 


+ .45 


— 1.02 


+ .10 


- .89 


— 


.88 


- .93 


670 


.88 


4 .40 


8 1.04 


2 .10 


6 .94 


840 


.85 


4 1 01 


+ 


.78 


+ .35 


-1.07 


+ .10 


- .99 


— 


.83 


-1.10 


1 


.77 


5 .40 


9 1 03 


3- .10 


7 .80 


1 


.87 


5 1 08 


+ 


.77 


+ .44 


- .99 


- .30 


- .61 


— 


.90 


-1.05 


2 


.73 


6 .35 


740 1.01 


4- .40 


8 .56 


2 


.87 


6 .82 


+ 


.69 


+ .27 


-1.02 


- .51 


— .52 


— 


.84 


- .62 


3 


.61 


7 .35 


1 1.00 


5 .57 


9 .44 


3 


.77 


7 .81 


+ 


.52 


+ .44 


— .98 


— .64 


- .36 


— 


.70 


— 1.00 


4 


.41 


8 .35 


2 1 01 


6 .77 


810 .34 


4 


.61 


8 95 


+ 


.31 


+ .25 


— 1.05 


- .91 


— .32 


— 


.53 


- .89 


5 


.26 


9 .20 


3 1.02 


7 .97 


1 .29 


5 


.42 


9 .94 


+ 


.22 


+ .16 


— 1.00 


-1.04 


- .26 


— 


.32 


- .99 


6 


.11 


710 .15 


4 1.04 


8 .98 


2 .21 


6 


.21 


880 . 76 




.0 


+ .14 


— 1.08 


- .92 


— .17 


— 


.11 


- .53 


7- 


.08 


1 .07 


5 1 07 


9 .87 


3- .09 


7 


.14 


1 .51 


— 


.16 


+ .01 


— 1.07 


- .82 


+ .01 


— 


.17 


- .50 


8 


.23 


2 .03 


6 .88 


780 . 94 


4 .04 


8 


.17 


2 .45 


— 


.31 


+ .05 


- .09 


-1.05 


+ .07 


— 


.18 


— .41 


9 


.32 


3 .06 


7 .69 


1 


5 .18 


9- 


.05 


3 .34 


— 


.33 


+ .07 


- .69 


— 1.05 


+ .29 


+ 


.08 


- .27 


680 


.38 


4+ .02 


8 .69 


2 1 04 


6 .31 


850 


.05 


4 .22 


— 


.43 


— .04 


- .69 


-1.03 


+ .34 


+ 


.03 


- .18 


1 


.49 


5- .02 


9 .55 


3 


7 .40 


1 


06 


5 .10 


— 


.55 


- .01 


— .41 


- 1 . 03 


+ .45 


+ 


.10 


- .01 


2 


.51 


6- .08 


750 .29 


4-1.00 


8 .44 


2 


.19 


6 .02 


— 


.48 


— .17 


- .17 


- .97 


+ .44 


+ 


.28 


- .03 


3 


5S 


7 .29 


1 .12 


5-1.02 


9 .50 


3 


.24 


7 .05 


— 


.61 


— .41 


- .08 


-1.07 


+ .55 


+ 


.21 


- .06 


4 


.61 


8 .50 


2+ .08 


6 1 00 


820 .56 


4 


.33 


8- .01 


, — 


.58 


- .58 


+ .24 


- .93 


+ .58 


+ 


.46 


4- .03 


5 


.55 


9 .72 


3 .14 


7 .96 


1 .60 


5 


.34 


9 .05 


— 


.53 


- .87 


+ .04 


— 1.00 


+ .61 


+ 


.22 


4- .08 


6 


.59 


720 .83 


4 .15 


8 1.00 


2 .52 


6 


.23 


890 .08 


— 


.65 


— .79 


+ .26 


- .99 


+ .43 


+ 


.24 


4- .09 


7 


.59 


1 .92 


5 .37 


9 .97 


3 .37 


7 


.41 


1 .06 


— 


.53 


-1.05 


+ .49 


— .96 


+ .31 


+ 


.58 


-t- .04 


8 


.43 


2 1 04 


6 .48 


790 .95 


4 .22 


8 


.40 


2 .03 


— 


.43 


-1.03 


+ .48 


- .95 


+ .13 


+ 


.22 


4- .02 


9 


.31 


3 1.04 


7 .49 


1 .97 


5 .10 


9 


.22 


3 .02 


— 


.19 


— 1.05 


+ .50 


-1.00 


4- .07 


+ 


.23 


- .02 


690 


.20 


4 .98 


8 .56 


2 1 03 


6— .08 


860 


.15 


4 .01 


— 


.21 


— .92 


+ .62 


-1.06 


- .22 


+ 


.09 


+ .01 


1 


.15 


5 .96 


9 .56 


3 1.05 


7 .30 


1 


.15 


5 .02 


— 


.10 


-1.01 


+ .50 


- 1.05 


- .39 


4- 


.20 


4- .03 


2— 


.03 


6 1 01 


760 .49 


4 1 01 


8 .50 


24- 


.10 


6 .04 


+ 


.03 


— 1.01 


+ .48 


- .98 


— .61 




.01 


4- .06 


3 


.01 


7 1 01 


1 .25 


5 1.01 


9 .67 


3- 


.04 


7- .01 







— 1 .02 


+ .03 


-1.04 


- .73 


— 


.07 


— .08 



496 



ELECTRIC RAILWAY TEST COMMISSION 



Table LXXII. — Continued. 

Note. — Plus sign (+) indicates up grade going east. 



^0- Grade 


^0- Grade 


^0- Grade 


^0' Grade 


^0- Grade 


^°' Grade 


Pole P^'^ 

No ^'^»' 
^0- Grade 


8 .04 


f .20 


5 .0 


- .09 


- .25 


— .27 


- .31 


- .01 


2 .14 


+ .02 


9 .12 


2 .26 


5 .25 


8 .30 


9 .06 


+ .08 


6- .04 


- .15 


- .28 


— .24 


- .30 


— .11 


3 .06 


— .10 


910 .20 


3 .19 


6 .26 


9 .38 


900 . 14 


+ .04 


7 .06 


- .24 


- .10 


— .28 


- .47 


- .27 


4 .0 


— .02 


1 .24 


4 .18 


7 .30 


920 


1- .03 


- .03 


8 .06 











Note. — -Large figures sho;v grades between poles, and small figures show 
grades at poles. 

The movable vestibule was hung from the front of the car 
body by means of two links. The vestibule was attached to 
the front of a steel and oak guide frame, which was restrained 
in its motion on all sides by small Chapman bearings specially 
constructed for this purpose. These bearings were mounted on 
rubber seats to relieve them from shock. The frame and vesti- 
bule were approximately balanced on the links, so that the 
guide frame exerted little force against the restraining bearings. 
The force exerted by the vestibule on the body was transmitted 
from a central point on the guide frame through a system of 
knife-edged levers to a dynamometer similar to that used for the 
car body pressure measurements. 

In order to eliminate all possible resistance between the mov- 
able car body and the supporting flat car, the controllers were 
mounted on iron stands projecting upward from the flat car 
floor. As the cables were very heavy and stiff, this feature was 
absolutely necessary. 

The trolley stand was supported on the top of a heavy oak 
post projecting upward through the car body floor from the flat 
car floor to a point about 6 ft. above the floor. The trolley base 
was, therefore, inside the car body, the trolley pole projecting 
through the roof and being bent at such an angle as to enable 
it to hold to the trolley wire. 

The air brake equipment was supported entirely from the flat 
car. The piping for the motorman's valve, the pneumatic track 
sanding device and the whistle, projected through the car body 



THE TEST CAR ['LOUISIANA'' 



497 



floor to a height convenient for the motorman, who was stationed 
inside the car body, and not in the vestibule. 

A set of twenty extra heavy resistance frames, supphed by 
the Westinghouse Electric and Manufacturing Company, was 
connected in the main trolley circuit for the purpose of controlling 
the current and therefore the speed of the car. These resist- 
ances were manipulated by means of a specially designed switch- 
board, so arranged as to enable the operator to short circuit any 
or all grids, and to connect the frames either in series or in 
parallel in any desired combination. 

EXTERIOR VIEWS OF THE CAR. 

Fig. 172 shows the car as it was arranged for the preliminary 
tests, and also for Test No. 59. The movable car body has a 




Fig. 173. — Sketch of "Parabolic " Movable Vestibule. 

standard vestibule attached at the rear, while the movable vesti- 
bule at the front is that of the "parabolic" form, a sketch of 
which is shown in Fig. 173. This constituted the original car 
body and vestibule which were built for the Commission by the 
J. G. Brill Company. While the car body and rear vestibule 
were of standard construction, the parabolic vestibule was 
specially designed and constructed by the Brill Company, in 
accordance with preliminary sketches furnished by the Execu- 
tive Committee. The vestibule proper was of sheet steel 
mounted on a steel framework, the hood being similar to the 
standard form of construction, excepting that it had to be spe- 



498 



ELECTRIC RAILWAY TEST COMMISSION 







THE TEST CAR ['LOUISIANA'' 



499 



cially designed to fit the parabolic vestibule. The hood formed 
a part of the movable vestibule, the latter being swung on sup- 
ports projecting from the front of the car body, as described else- 
where in this chapter. 

The sign show^n in the photograph of the car gives a list of the 
principal cooperating com.panies and reads as follows: 

Pkixcipal Cooperating Companies 
Indiana Union Traction Company 



J. G. Brill Company- 
Pressed Steel Car Company 
National Electric Company 
Fairbanks, Morse & Company 
Westinghouse E. and M. Company 



Baldwin Locomotive Works 

Weston Electrical Instrument Com- 
pany 

Chapman Double-Ball Bearing Com- 
pany 



Fig. 174 shows the car equipped with the "parabohc wedge" 
vestibule used in Test No. 58. The general construction does 
not differ from that shown in Fig. 172, excepting in the form of 




Fig. 175. — Sketch of " Parabolic Wedge " Movable Vestibule. 

the vestibule, a sketch of which is shown in Fig. 175. The 
wedge shape was obtained by building out a wooden framework 
attached to the parabolic vestibule, and by covering this frame- 
work with a galvanized iron sheathing. As seen from the photo- 
graph, the flat surface of the wedge began at a point just forward 
of the small side windows of the parabolic vestibule. Two large 
windows were placed in the wedge so as to enable the motorman 



600 



ELECTRIC RAILWAY TEST COMMISSION 




3 



THE TEST CAR ''LOUISIANA'* 501 

to have a good view of the right of way. Some httle difficulty 
was experienced in building out the hood of the parabolic vesti- 
bule to conform to the parabolic wedge conditions, but this was 
finally accomplished in a satisfactory manner. The standard 
form of vestibule was attached to the rear of the movable car 
body during the tests in which the parabolic wedge vestibule was 
employed. 

The "flat" form of movable vestibule is shown in Fig. 176, 
and was the one employed in Test No. 60. The standard form 
of vestibule was attached at the rear of the movable car body 
during these tests. The movable vestibule in this case con- 
sisted essentially of a flat surface, which conformed to the gen- 
eral contour of the cross-section of the car body. It was built 
up with light matched lumber mounted on a steel and iron frame- 
work, three large windows being included in the construction for 
purposes of observation. The large bell crank lever shown in 
the photograph was not in position at the time Test No. 60 was 
made. As stated elsewhere, this lever was constructed for the 
purpose of obtaining a calibration of the dynamometers by 
means of direct pressure and tension measurements. 

DETAILED DESCRIPTION OF THE CAR. 

The Driving Equipment. 

The Flat Car. — The foundation of the dynamometer car was 
a pressed steel flat car of 100,000 lbs. capacity, loaned to the 
Commission by the Pressed Steel Car Company of Pittsburgh, 
Pa. The construction of this car is illustrated in Fig. 177. 

It consists essentially of a pair of extra heavy center sills, 
connected above by a steel plate firmly riveted to the sills. The 
sills are braced by means of angles riveted to the bottom edge, 
and they are cross-connected by Tee bars. The side sills are 
of the dished pattern, and these were also stiffened by means of 
angles riveted at the top and bottom. All of the sills were con- 
nected by cross angle-bars spaced about 3 ft. apart. The bol- 
sters were extra heavy, and were located about 5 ft. from 



502 



ELECTRIC RAILWAY TEST COMMISSION 




THE TEST CAR ['LOUISIANA" 503 

the ends of the flat car body. Ordinary M. C. B. couplers were 
supplied, but no use was made of them in the tests except to sup- 
port two specially constructed bumpers described below. A 
pressed steel body center plate was located in the middle of each 
bolster. Longitudinal stringers supported the heavy floor. The 
ordinary trucks and brake rigging of the car were removed, and 
only the parts described were employed in the air resistance 
tests. 

In order to prevent injury to other cars with which the test 
car might come in collision, tw^o special bumpers were con- 
structed. These bumpers consisted of steel bars five inches by 
one inch, and bent into such a form as to furnish fiat surfaces at 
the standard coupler level, and upon these surfaces were moimted 
heavy oak blocks securely bolted to the bars. At one end, the 
bar was mounted on the coupler and secured thereto by the 
regular coupler pin. At the other end, it was bolted to the sup- 
porting framework. By this mounting a considerable flexibility 
was secured in addition to the natural spring of the bar, through 
the fact that the main shock was taken by the coupler springs. 

The Trucks. — The trucks employed were of the Baldwin loco- 
motive type M. C. B. interurban trucks with the Gibbs cradle 
suspension, described in Chapter I and illustrated in Fig. 20. 
These trucks were loaned to the Commission by the Indiana 
Union Traction Company. A sketch of the standard form of 
this truck is shown in Fig. 21, Chapter I. 

In order to allow the trucks to rotate sufficiently to enable 
the car to round curves of small radius, it was necessary to con- 
struct special high center plates and side bearings, which was 
done for the Commission by the Baldwin Locomotive Works. 
Fig. 178 shows the details of the changes made in the center 
plate and side bearings, while Fig. 179 shows how the height 
necessary for the proper clearance between the sills and the 
wheels was calculated. 

Braking Equipment. — No change was made in the brake 
equipment supplied with the Baldwin trucks, but it was neces- 
sary to construct a special brake rigging to permit the use of the 



604 



ELECTRIC RAILWAY TEST COMMISSION 




Fig. 178. — Sketch Showing Details of Changes Made in Center Plates and Side Bearings 

of Baldwin Trucks. 




Fig. 179.— Sketch Showing Changes in the Baldwin Trucks to Accommodate the Flat Car, 



THE TEST CAR [[LOUISIANA" 505 

air brake in connection with the flat car. The entire brake 
equipment, with the exception of the parts constructed by the 
Executive Committee; was supplied by the National Electric 
Company. 

The brake cylinder was mounted on steel strips himg from the 
bottom of the cross-bars at the middle of the flat car. The bars 
which connected the ends of the levers to the transoms were one 
inch by five inches, and were bent in such a form as to enable 
them to clear the various parts of the flat car frame. The ends 
of these bars were forged into a U-shape, so as to span the tran- 
soms and support a pair of rollers, which served to deliver the 
force to the transoms without undue friction. The tension bars 
were prevented from side motion by a guide hung from the 
center sills. In order to provide against any possible accident 
to the air braking equipment, a hand brake equipment was in- 
stafled. This was equipped with drimis of the Peacock type, 
supplied by the National Brake Company. These drums have 
a spiral form, which brings the chain nearer to the spindle as the 
chain is wound up. The drums are largest at the end to which 
the brake chain is attached, so that the slack is quickly taken 
up and the tension on the chain increases as the drum is rotated. 
The hand brake rigging, as well as the piping for the air brake 
equipment, was moimted on the flat car floor and projected 
through openings in the car body floor. 

The motor-compressor was mounted near the center of the 
car, under the floor, and suspended from two adjacent cross- 
angles by steel straps which were hung from the tops of the 
angles, and which passed under the base of the compressor. 
The compressor was entirely inclosed, but it was so located 
that there was sufficient space between the box and the side 
sills to permit of the removal of the sides of the box. This 
made it possible to inspect the commutator and to oil the 
machine. The reservoir was located above the floor of the flat 
car near the compressor. 

The governor was also located on the flat car floor, and was 
accessible from above by means of a trap door in the car body 
floor. 



606 ELECTRIC RAILWAY TEST COMMISSION 

Motor Equipment. — Upon the trucks were mounted four 
No. 85 We3tinghouse motors geared for a speed of 60 miles an 
hour, the gear ratio being 27 to 47. These motors were similar 
to the standard equipment of the Indiana Union Traction 
Company, by which the motors were loaned to the Commission. 

For the purpose of these tests the motor fields were shunted 
through iron grid resistance frames, furnished by the Westing- 
house Electric & Manufacturing Company. These grids were 
mounted beneath the floor of the flat car, and were so arranged 
that the shunt resistance could be increased or decreased with 
little trouble by means of suitable switches. 

Controller and Wiring. — While the standard cars of the 
Indiana Union Traction Company are supplied with but one 
controller, it was quite essential to provide a double-ended 
equipment for these tests. The Traction Company loaned one 
Type L-4 Westinghouse Controller, and the Westinghouse Elec- 
tric & Manufacturing Company loaned a duplicate one. The 
^Traction Company also supplied a set of cables for a single-ended 
equipment. It was necessary, therefore, for the Executive 
Committee to rearrange this wiring to fit it to a double-ended 
controller equipment. 

As the wiring had to be done on as economical a basis as pos- 
sible, it was decided to make up the new cables of weather- 
proof wire. 'No. B & S gage wire was used for all of the 
motor and resistance connections, and No. 000 B & S gage 
rubber covered cable was used for the trolley and groimd con- 
nections. The starting resistance grid frames v/ere mounted 
upon the flat car floor. They were thirteen in number, and 
were connected in accordance with the standard practice of 
the Traction Company, as shown in Fig. 180. This diagram 
also gives details of the wiring and of the controller connec- 
tions. The wiring cables were covered with canvas cable hose, 
which was laid directly upon the flat car floor. 

In order to prevent any imnecessary connection between the 
upper part of the car and the driving equipment, the controllers 
were mounted upon bent steel frames which projected upward 



THE TEST CAR ['LOUISIANA'' 



607 




5 









508 



ELECTRIC RAILWAY TEST COMMISSION 



from the flat car floor through the car body floor without 
touching the latter. All cables were brought up inside these 
frames, and were thus kept entirely free from the car body. 
The controller and controller-supporting frames also served as 
the support for the air brake and whistle piping. 

Other Driving Mechanisms. — Each truck was provided with 
pneumatic Sanders consisting of iron boxes mounted upon the 
truck frames, with openings which delivered sand directly in 
front of the wheels. The sand valves were operated by means 
of compressed air, the air valve being placed close to the air 
brake valve. 




I CIA "T- ^A.r^^t^-*^^CS li 



FLAT CAR FCOOF^ 



-tts 



Fig. 181. —Sketch Showing General Arrangement of Safety-Locfting Device and 

Car Body Dynamometer. 

The car was supplied with a chime whistle for use in the open 
country, and with a large foot gong for use in cities. A Mosher 
head-light for use on night runs was a part of the equipment, as 
were also the usual trolley retrievers and other sundry equipment 
necessary for the operation of a high speed car. 

Car Body Equipment. — Lengthwise upon the flat car floor, 
and 6 ft. 4 in. between the insides of the heads, were mounted 
two steel rails weighing 45 lbs. per yard. These were secured 
to the floor by means of lag screws. These rails were straight, 
carefully leveled, and were polished at those places where the 
car body wheels rolled. 

To the center of the flat car floor was secured a 6-inch by 
8-inch Georgia pine timber 20 ft. in length, which was bolted 



THE TEST CAR ['LOUISIANA'' 



50d 



at several places to the steel plates of the center sill of the flat 
car. This timber was used to support the driving and safety 
mechanisms of the movable car body. One of the two safety 
locking devices used is shown in Fig. 181, while a more detailed 
view^ is given in Fig. 182. 

The Movable Car Body. — A special interurban car body was 
supplied for these tests by the J. G. Brill Company. In order to 



CEN'TER 3ILL 




FLAT CJ^ FLOOR 
Fig. 182.—Dstailed Sketch of Safety-Locking Device. 



render it as light as possible, and to provide the necessary room 
inside the car body, it was not lined, and all unnecessary parts 
were omitted. The body was 32 ft. in length over corner posts, 
8 ft. 4 in. in width outside, and the height from the bottom of 
the side sills to the top of the roof was 9 ft. 4 in. A sketch 
of the cross-section is shown in Fig. 183. 

The body was mounted upon eight 12-inch wheels specially 
chilled for the purpose by the American Car & Foundry Com- 



510 



ELECTRIC RAILWAY TEST COMMISSION 



pany. They were pressed upon four Sy^-inch steel axles, 9 ft. 
in length. Fig. 183A shows a general sketch of the wheels and 
axle. The treads of these wheels were ground, after they were in 




Fig. 183. — Cross Section of Car Body of " Louisiar'a." Tliis Slietch Also Shows the General 
Dimensions of the "Flat" Movable Vestibule. 




FINISH -TREAD 

Fig. I83A. — General Stietch of Wheels and Axle for Mounting Car Body, Showing Dimensions. 

position, by means of curved blocks formed to fit the surface of 
the wheel; emery powder mixed with oil being used as an abra- 
sive. The blocks were held against the wheels by means of 
springs, and the wheels were driven by an electric motor belted 
to a pulley mounted on the axle. The wheels were so hard 



THE TEST CAR "LOUISIANA'' 



511 



that a week or more was consumed in grinding the .surfaces of 
the treads perfectly smooth. 

The axles were carried by Chapman double-ball bearings, 
which are illustrated in Figs. 184 and 185. The general method 
of mounting the bearings is shown in Fig. 186, while Fig. 187 
gives the mounting more in detail. As the success of the ex- 
periments depended to a considerable extent upon the char- 
acter of the bearings employed, a brief description of the bear- 
ings selected will be of interest. As is evident from the illustra- 




Fig. /84. — Gene fa/ View Chapman Double-Ball Bearing. 



tion, the bearings consist of two rings of large balls carried 
between cones, one on each of the hubs. The cones are of hard 
tool steel, and are adjusted by means of screw threads. A fea- 
ture peculiar to the Chapman bearing is the fact that the balls 
are spaced by means of small intermediate balls, each of which 
is carried in a small cage. The spacing balls are so arranged 
that there is no slipping between any pair of adjacent large balls. 
The hub of the bearing slips loosely over the shaft to be driven, 
which is free to revolve inside the hub in case the friction in the 



512 



ELECTRIC RAILWAY TEST COMMISSION 



ball rings becomes excessive for any reason. The hub is cov- 
ered at each end by a pressed steel dust proof case. In the test, 
tin hoods were built over the ends of the bearings to protect 
them from the weather. 

The four supporting axles were placed under the car body in 
such a way as to distribute the strain uniformly along the rails. 
When thus mounted, the body rolled freely upon the rails, a 
force of a few pounds being sufficient to start it. 

The Vestibules. — Four types of vestibule were employed in 
connection with the tests: (1) a vestibule with a parabolic sec- 




Fig. 1S5. — Pressed Steel Duct-Ring of Chapman Double-Ball Bearing. 



tion; (2) a vestibule with a wedge-shaped section; (3) a standard 
interurban vestibule; and (4) a flat surface, representing the 
front of a perfectly square-ended car. 

The parabolic vestibule was constructed of light sheet steel 
built upon a steel angle iron framework. This vestibule was 
constructed for the tests by the J. G. Brill Company. Figs. 172 
and 173 show the general construction of this vestibule and its 
dimensions. It conformed in outline to the front of the car, and 
was provided with a hood of the Pullman type. The weight of 
this vestibule was approximately 1900 lbs., including the guide 
frame. 



TH^ TEST CAR ['LOUISIANA 



61^ 



As the general construction did not permit of a motorman 
standing in the vestibule, a special bent glass front was con- 
structed by the Executive Committee in order to give the motor- 
man as good a view of the track as possible. A plate of double 
thick window-glass was bent by a local firm to conform to the 
exact curvature of the front. An aperture was cut in the steel 
sheathing and around the edge of this was placed a strip of thick 
felt. A wooden frame was sprung against the inside of the 
sheathing to support the glass, and, after the glass was placed 
against the felt strip, a second felt strip was placed over it, and 
strips of thin steel were screwed firmly against this felt. This 




Fig. 186. — Sketch Showing General Method of Mounting Chapman Double-Ball Bearings. This 
Sketch Also Shows General Arrangement of the Car Body Dynamometer Lever. 

construction served to hold the glass in position without having 
it come in contact with any hard surface. The glass was 
specially annealed to protect it from the strains which would 
be caused by constant changes in temperature. 

After the vestibule was placed in position in the car, the con- 
tour of its surface was continued downward with sheets of thin 
steel to the top of the flat car floor, to prevent currents of air 
from circulating underneath it and introducing errors into the 
measurements. 

The "parabolic wedge" vestibule was produced by building 
a wooden framework out from the parabolic vestibule and cov- 
ering it with sheet steel, as shown in Figs. 174 and 175. The 
roof was molded to conform with the general contour of the 



514 



ELECTRIC RAILWAY TEST COMMISSION 



cross-section of the car, and when this was equipped, the vesti- 
bule weighed approximately 2150 lbs. including the guide frame. 
Flat windows were provided on the sides of the wedge in front 
of the curved glass of the parabolic vestibule. 

The standard interurban vestibule was one such as is usu- 
ally constructed for use with this type of car body, and was also 
supplied by the J. G. Brill Company. This vestibule had a sec- 
tion as shown in Figs. 188 and 189, and it weighed 1230 poimds 




Fig. 187. — Sketch Showing Details of Mounting Chapman Double-Ball Bearings. 



when complete and hanging on the dynamometer frame. This 
vestibule had a curved front with a radius of curvature of 5^ 
ft., and the front was equipped with the usual sashes. Double 
doors, 2 ft. 10 in. in width, closed the openings at the sides. 
The roof of this vestibule conformed in outline to the contour 
of the car body, and was supplied with a standard hood of the 
Pullman type. 

The flat vestibule consisted of a light framework covered with 
planking, and having a form corresponding to the cross-section 
of the car as shown in Fig. 183. It weighed 730 lbs. when 



THE TEST CAR "LOUISIANA" 



515 



equipped with window-sashes and the devices for hanging it 
from the dynamometer frame. 

All of the vestibules, when hanging upon the dynamometer 
frame, were connected with the car body by a strip of light cloth, 
which served to prevent eddies of air between the vestibule 
and the front or rear of the car body. 

Vestibule Mounting. — In order to support the vestibule by 




Fig. 188. — General Sketch of "Standard" Vestibule, Showing Method of Attachment 

to Car Body. 

a mechanism involving as little friction as possible, it was de- 
cided to hang the vestibule from a pair of Hnks carried over 
two heavy oak timbers projecting through the front of the car. 
To the ends of these timbers were attached eye bolts, from which 
hung a pair of links connected at their lower ends to eye bolts 
carried by steel brackets, attached to vertical steel strips form- 
ing part of the vestibule. These links were of such a length that 
the vestibule could swing a short distance without serious fric- 
tion. To the rear of the vestibule was attached a guide frame 



516 



ELECTRIC RAILWAY TEST COMMISSION 



constructed of light oak timbers with diagonal truss rods of 
steel on all sides. The method of mounting is shown in Fig. 190, 
which is a general sketch showing the elevation and plan of the 
car. Each truss rod contained a turn buckle so that the shape 
of the frame could be altered to a certain extent to insure its 
being absolutely square. This frame was approximately four 
feet by six feet outside, and it had a total length of eight feet. 
In addition to the truss rods, there were also two cross braces 
at the rear of the frame, built of flat steel three-fourths inch by 
three inches in section. These cross braces served to render the 




Fig. 189. — Detuned Sketch of "Standard" Vestibule. 

guide frame absolutely rigid. Its main purpose, however, was 
to form (at its center) a point of attachment for the pressure 
measuring dynamometer. The four longitudinal timbers of the 
guide frame were shod at their front ends with steel strapi^ 
which projected through holes cut in the front of the car body, 
and which were bolted to the vertical steel strips attached to 
the back of the vestibule. The guide frame thus formed aa 
integral part of the vestibule equipment. 

The guide frame served two general purposes: first, it moved 
between guide bearings on all sides so that it held the vestibule 
in its proper position, and second, it counterbalanced the weight 



THE TEST CAR "LOUISIANA'* 



517 



I 




CD 



00 



c ■ 



518 ELECTRIC RAILWAY TEST COMMISSION 

of the vestibule. The guide bearings (twelve in number) were 
one inch Chapman double-ball bearings, similar in general form 
to the larger bearings used in mounting the car body. They 
were carried in cast-iron "forms upon small pieces of one-inch 
shafting. The bearings required special fitting for this work, 
as it was desired to have them bear upon the sides of the guide 
frame. The flanges at the ends of the hubs were turned off 
perfectly smooth, and the dust caps were removed. In order 
to take up the shock wdiich mught be transmitted to the bear- 
ings from the guide frame, the bolt holes in the bearing frames 
were countersunk, both above and below, and rubber washers 
were fitted into the recesses thus formed. The heads of the 
bolts used to clamp the bearing frames to the support did not, 
therefore, at any point come in contact with iron. This pro- 
vision was effective in taking the sudden jars off the bearings 
themselves. Flat steel plates were screwed to the sides of the 
oak frame at the places where the guide bearings were located. 

THE PRESSUEE-MEASURING EQUIPMENT. 

The Dynamometers. — One of the most difficult problems 
in connection with the tests was that of obtaining a pressure 
measuring device which would weigh accurately the pressure 
upon the vestibule. The Executive Committee w^ould have pre- 
ferred to have constructed a rotating piston oil dynamometer 
with various diameters of piston for use at different pressures. 
This was found to be out of the question, on account of lack 
of time, and for that reason it was decided to adopt some form 
of scale beam which could be obtained upon the market. The 
scale finally selected was one constructed by Fairbanks, Morse 
& Company, and called an automatic, self -indicating, quick- 
weighing beam. The essential features of this beam are shown 
in Fig. 191. 

The beam is 30 in. in length, and it is supported approxi- 
mately 4 in. from one end by a knife-edged link suspension. 
The link hangs upon a hook carried by a vertical stand which 
is mounted upon a low table. The force is transmitted to the 



THE TEST CAR ['LOUISIANA 



519 



beam through a knife-edged Unk, 3to in. from the suspension 
knife edge. The weights are carried on a platform hung from 
a Hnk suspension 16^ in. from the supporting Unk, this plat- 
form being large enough to carry weights equivalent to 1500 
lbs. A spring balance with a large dial was connected between 
the bottom of the scale pan and the table, with a screw ad- 
justment for setting the zero. The dial of the balance was 
divided into 200 parts, a complete revolution of the pointer 




Fig. 191. — General Sketch of Scale Mechanism Used with Dynamometefs. 

being nominally equivalent to 200 lbs. In addition to the 
weights carried by the scale pan, a movable poise with set 
screw and having a maximum value of 100 lbs., was carried 
on the beam. 

To the end of the beam was attached a rod, at the lower end 
of which was a metal disk, submerged in oil in a cast-iron recep- 
tacle. This formed a dash-pot for absorbing the vibrations 
of the beam. The dash-pot ordinarily used with the beam 
was of sufficient size in the case of the vestibule dynamometer^ 



520 ELECTRIC RAILWAY TEST COMMISSION 

but for the car bociy dynamometer, a larger dash-pot was con- 
structed, as the vibrations in this case were very great. The 
beam was supplied with a counterbalance and with a lock for 
holding the beam securely in place when not in use. 

The Lever Systems. — The point of attachment for the meas- 
urement of the vestibule pressure was at the center of the diag- 
onal cross brace at the rear of the vestibule guide frame. A 
steel plate was bolted to the brace at this point and in this plate 
were bored holes, the edges of which were rounded for the knife- 
edge link attachments. At the front of the frame the pressure 
measuring lever was attached, while at the rear the counter- 
weight lever was connected by means of a suitable link. 

The pressure was transmitted from the guide frame through 
a link in a knife-edge bell-crank lever which latter served to 
turn the force from a horizontal to a vertical direction. From 
this bell-crank, a link transmitted the force to the end of a hori- 
zontal lever carried in a floor stand. The other end of this 
lever was attached directly to the tension rod of the weighing 
beam. All knife edges were of hardened tool steel, and they 
were mounted in round holes in steel straps, the holes being 
bored somewhat larger than the diameter of the steel on which 
the knife edges were ground, so that in no case would there be 
any contact, except through the knife edges. 

As it was necessary to take the readings of the dynamometer 
with the car going in both directions, and as the dynamometer 
would only read in one direction, a constant pressure was main- 
tained between the guide frame and the lever system by means 
of a coimterweight applied to the guide frame through a sys- 
tem of levers. This counterweight pressure was maintained 
at approximately 350 lbs. This counterweight served also to 
steady the vestibule, especially at high speeds. 

The car body dynamometer was similar to that employed 
for the vestibule except for the larger dash-pot, as already men- 
tioned. Pressure was transmitted from the flat car to the car 
body through a system of levers somewhat similar to that already 
described. .vThe point of attachment in this case was the steel 



THE TEST CAR ['LOUISIANA" 



521 



frame forming a part of one of the safety locks. Figs. 181, 186, 
and 190 show the details of this attachment. A rod turned 
perfectly smooth was carried through two holes bored in the 
large wrought-iron strap of the safety lock frame. The rod was 
threaded for a length of 4 in. inside the frame, and this 
thread carried a tension nut which was screwed against a stiff 
spring mounted over the rod. The purpose of this spring was 
to take up lost motion in the lever system. When the tension 
was on the rod, the tension nut was drawn down against an iron 
tube which was slipped loosely over the spring. The tension 
rod was connected through links to a double hook which was 



OAK 
POST 




_44«-^-o''->) 



■^-^> '^^^J^^^^J V^^TTTS 



FLOOR BEAM 



TIX^BER Orv FU/VT C ». f\ 



Fig. 192. — Sketch Showing General Arrangement of Car Body Counterweight. 

connected to one arm of a bell-crank lever carried in a bearing 
between the center of the sills of the car body. The other arm 
of this bell-crank lever transmitted the force through a link to 
the short arm of a second lever, which was supported by bear- 
ings mounted beneath the sill. The long arm of this lever was 
connected directly to the tension rod of the dynamometer. The 
general arrangement of the dynamometer lever below the car 
floor is shown in Figs. 181 and 186. 

The matter of counterweighting the car body in such a manner 
as to produce a steady pressure upon its dynamometer was 
found to be a most important matter. The coimterweight 
lever shown in Fig. 192 was constructed to produce a pressure 
of approximately a thousand pounds against the dynomometer 



522 ELECTRIC RAILWAY TEST COMMISSION 

Sit all times. The tension rod for this counterweight lever 
was attached to one of the beams beneath the car body, and 
this tension rod was supplied with a turn-buckle for the purpose 
of adjusting the position of the lever. The lever was made in 
the shape of a large T in order to provide a convenient method 
of stiffening it, which was done by means of a truss rod. The 
tension rod was attached to the lower end of one of the short 
arms of the "T" and the whole lever was carried in a bearing 
supported by the trolley post. Cast-iron weights were carried 
at the end of the lever. 

THE TROLLEY SUPPORT AND STAND. 

One of the essentials in obtaining the pressure on the car body, 
was to have it perfectly free from all fixed connections with the 
flat car. It was also necessary that the trolley connection be 
made in the ordinary way, by means of a trolley pole projecting 
from the roof of the car. 

In order to accomplish the desired results an oak tie was used 
as a trolley support. This tie was dressed to a cross-sectional 
area of 5 by 7 inches, the length being 8 ft. It was placed on 
end at a point near the center of the car, and secured to the 
center beam fastened to the floor of the flat car. It was braced 
to the flat car by means of tension rods and turn-buckles. This 
support projected through the floor of the movable car body, 
passing between the two center sills. In order to have no con- 
tact between the car body and the trolley support, the floor of 
the former was cut away so as to leave an opening of approxi- 
mately IJ inches between it and the support. This permitted 
of the free movement of the car body on the dynamometer. 
In Hke manner, the flooring of the car body was cut around the 
tension rods which braced the trolley support. The general 
arrangem.ent is shown in the sketch given in Fig. 190. 

On top of this support was securely fastened an oak slab 
2 inches thick, the dimensions of which were approximately 
12 by 20 inches. Upon this slab was mounted a ball-bearing 
trolley stand. This trolley stand was remodeled to suit the 



THE TEST CAR ''LOUISIANA'' 523 

special conditions involved. It was necessary that the trolley 
pole pass vertically through the roof, in order that a small open- 
ing in the latter might suffice to permit of the free movement 
of the trolley pole to conform to variations in the height of the 
trolley wire above the ground. 

As it was necessary that the trolley pole should project from 
the car roof at a considerable angle with the vertical, the pole 
was bent at a sharp angle at a point just above the roof of the 
car. This angle was predetermined by knowing the average 
height of the trolley wire, the height of the car roof above the 
track, and the length of the trolley pole. The angle selected 
was that which would place the trolley wheel in contact with 
the trolley wire at an average height, when the base of the 
trolley pole was in a vertical position. The tension springs on 
the trolley stand were adjusted for this condition. 

Upon running the car at high speeds, it was soon discovered 
that the trolley support vibrated considerably from side to side. 
This vibration was eliminated by means of a light guide frame, 
built out from the oak slab at the top of the trolley support. 
This guide frame consisted essentially of wooden cross-pieces 
cushioned against the longitudinal deck beams in the roof of 
the car, rubber buffers being provided for this purpose. It is 
seen from this brief description that the current was conducted 
from the trolley wire to the flat car by means of a support which 
was entirely free from the movable car body. 

THE OIL CYLINDER BUFFERS. 

During the preliminary tests made in Januar}^, 1905, it was 
found that the surging of the car body at high speeds, due to 
changes in grade or acceleration, was so excessive as to seri- 
ously impair the results of the dynamometer readings. This 
was due to the fact that the car body had a considerable inertia 
effect, weighing, as it did, approximately 21,000 lbs. 

In order to overcome this difficulty, or at least to reduce it 
so that it would not prove to be a serious objection, it was de- 
cided to construct some form of buffer so that the car body 



524 ELECTRIC RAILWAY TEST COMMISSION 

would react upon the flat car. The method employed is illus- 
trated in Fig. 190. Two Christensen air brake cylinders 10 inches 
in diameter were securely lagged to the floor of the movable car 
body, after the springs had been removed from the interior 
of the cylinders. These cylinders were placed one in front of 
and the other behind the trolley support, described above, and 
which was built up from the flat car. Suitable bearings were 
constructed and placed on the trolley support, in such a posi- 
tion as to take the thrust of the plungers operated by the pistons 
in the cylinders. Holes were bored in the back cylinder heads, 
and a l^-inch pipe was connected to the cylinders so as to pro- 
vide a passage between them and back of the piston in each 
case. Oil was pumped into the cylinders, and the plungers 
were forced out against the bearings on the trolley support. 

By this arrangement a cushioning effect was produced as 
soon as the car body commenced to vibrate with reference to the 
flat car. One piston would be forced further back in its cylinder, 
and oil would be forced around from that cylinder into the other 
one. The flow of the oil between the two cylinders could be 
regulated by means of a gate valve, which formed a part of the 
piping connecting the two cylinders. Some little leakage oc- 
curred, but this did not prove to be of any considerable moment. 
It was found necessary to pump oil into the cylinders at inter- 
vals, in order that the plungers might be kept pressing against 
the trolley support on both sides. 

Various kinds of oil were used in these cylinders, and the 
apparatus was tried under many different conditions of opera- 
tion. Kerosene oil was first used, but this was found to be too 
light and, furthermore, it was decidedly objectionable from the 
standpoint of fire, as it leaked past the pistons very readily, 
and ran down on the floor of the flat car. Cylinder oil was 
tried, but was found to be too heavy for the purpose. The oil 
which was most successful was a motor oil, such as was used 
by the Indiana Union Traction Company on its interurban 
motor cars. 

Experiments were also made to determine the effect of having 



THE TEST CAR ['LOUISIANA" 



625 



the cylinders pumped up so that the plungers pressed tightly 
against the trolley support, and, again, of permitting some con- 
siderable lost motion in this buffing device. The best results 
were obtained with the plungers pressed tightly against the 
trolley support. 

WEIGHTS OF CAR BODY VESTIBULES FOR THE VARIOUS TESTS. 

In order to make the proper corrections for grade and accel- 
eration, it was necessary to know the w^eight of the movable 
vestibule, and also that of the movable car body, for each series 
of tests. 

A complete inventory was made, covering all of the compo- 
nent parts of the various equipment which entered into the 
general assembly of the movable car body and vestibule. The 
actual weights of the major portion of the equipment were 
already available, and where the weights were lacking in any 
given place, the particular piece of apparatus or component 
part of the construction was carefully measured, and its weight 
estimated from the volumes of the various materials contained. 
There were on an average, eight observers (including, mot orman 
and conductor), and the total- live weight was estimated at 
1200 lbs., or 150 lbs. per man. 

The total weights are summarized in the following table, 
which shows the fixed vestibule, the car body, the movable 
vestibule, and the total weight for each of the various tests. 



Weights of Car Body and Vestibule {in pounds) for the Various Tests. 




Test Number. 




58 


59 


60 


61 


Fixed Vestibule 


970 

17,930 

2,250 

21,150 


970 

17,930 

2,100 

21,000 


970 
17,930 

730 
19,630 





Car Body Alone 


17,930 

1,430 

19,360 


Movable Vestibule 


Total Weight 





526 ELECTRIC RAILWAY TEST COMMISSION 

The various tests referred to in this table are those consid- 
ered in Chapter XVI. The vestibules employed were as follows : 

Test No. 58. — " Parabohc-wedge " movable vestibule, stan- 
dard fixed vestibule. 

Test No. 59. — "Parabohc" movable vestibule, standard 
fixed vestibule. 

Test No. 60. — "Flat" m.ovable vestibule, standard fixed 
vestibule. 

Test No. 61. — "Standard" movable vestibule, no fixed 
vestibule. 

electrical connections. 

As has already been stated, the controllers were placed inside 
the car body, being mounted on iron shoes fastened to the floor 
of the flat car, and brought up through openings in the floor of 
the movable car body, the flooring being cut away so as to per- 
mit of the free movement of the car body. The trolley pole 
was supported on an oak post built up from the floor of the flat 
car. The general construction necessitated that the motorman 
should operate the car while standing on the floor of the movable 
car body. A controller was placed at each end of the car, as 
was also a circuit-breaker. 

It was necessary that arrangements be made whereby addi- 
tional resistances could be readily inserted in the trolley cir- 
cuit, in order that the speed of the car might be governed by 
the observers. This was done by means of sixteen frames of 
starting grids, loaned by the Westinghouse Electric & Manu- 
facturing Company, which were connected to a special switch- 
board in such a manner that they could be introduced into the 
circuit in various combinations. The general wiring scheme 
was essentially as follows: 

A'No.OB&S gage rubber covered cable was connected to 
the trolley stand, and was brought to the roof of the car body 
in a loop which was approximately 6 ft. in length. This loop 
permitted of a flexible connection between the trolley support 
and the movable car body. The cable was carried along the 



THE TEST CAR ['LOUISIANA" 527 

roof of the car body to the circuit-breaker at the rear of 
the car. 

After passing through this circuit-breaker, the trolley circuit 
was run direct to the switchboard, pjid from there to the cir- 
cuit-breaker at the front of the car. From this circuit-breaker 
the line was brought back to the center of the car, and looped 
down to the trolley support by means of a flexible No. rubber 
covered cable, in a manner similar to that employed in passing 
from the trolley support to the roof of the car body. The cir- 
cuit was then continued down the trolley support, and connected 
to the trolley lead in the car wiring cable. From this point, 
connections were such as would ordinarily be used in an equip- 
ment with two Type L-4 controllers and four Westinghouse 
No. 85 motors. The car wiring cables were placed on the floor 
of the flat car, as were also the regular starting grids used in 
connection with this equipment. 

The switchboard consisted essentially of an oak panel, upon 
which were mounted sixteen single-pole single-throw knife 
switches, and the connection board below, by means of which 
the resistance grids could be connected in various combina- 
tions relative to the switchboard. The resistance grids were 
placed on either side of the car underneath the benches at the 
rear. Taps were brought out from various panels of these grid 
frames and connected either to the distributing board or to the 
main switchboard. By this arrangement, the grids could be 
connected in various combinations on the distributing board 
in a manner similar to that ordinarily employed in making the 
connections between the coils of transformers. With a given 
combination on the distributing board, the main switchboard 
could be employed to short circuit this extra resistance alto- 
gether, or to vary it between the limits of the combination. 

INTERIOR VIEWS OF THE CAR. 

The interior of the car, looking toward the front from the 
rear vestibule, is shown in Fig. 193. Benches were constructed 
on either side of the car at the rear for the purpose of placing 



528 



ELECTRIC RAILWAY TEST COMMISSION 



instruments in positions convenient for observation and for 
general use in the testing work. Under these benches were 
located the extra resistance grids connected to the switchboard. 
The general construction of the trolley support is shown very 
clearly in the center of the picture, as is also the oil cylinder 




Fig. 193. — Interior View of Car "Louisiana," Loofting Toward the Front from 

the Rear Vestibule. 

buffing device. The switchboard is shown on the right at the 
center of the car, and the dynamometers are on the left, in front 
of the trolley support. 

Fig. 194 shows a view of the interior of the car looking toward 
the rear from the front or movable vestibule. The general 
construction of the vestibule and guide frame, the supporting 
timbers for its suspension, and the general mechanism of the 



THE TEST CAR ''LOUISIANA 



629 



weighting devices, are all clearly brought out in this photograph. 
The switchboard appears on the left, and the resistance grids 
and one controller are seen at the rear of the car. 

A view taken from a position between the trolley support and 
the switchboard, and looking toward the front of the car, is 
shown in Fig. 195. This photograph was taken for the purpose 
of showing more clearly the general construction of the weight- 




Fig. 194. — Interior View of Car "Louisiana," Looking Toward the Rear from 

the Front Vestibule. 

ing mechanism, as well as some of the details of the movable 
vestibule guide frame. The counterweighting device for the 
movable vestibule is shown in the photograph, and consists of 
a series of levers extending from the dynamometer support to 
the roof of the car, the counterweight itself hanging on the end 
of the lever supported from the car roof. The end of the lever 
employed in counterweighting the car body is shown in the 
foreground and toward the right of the photograph. It con- 



5S0 



ELECTRIC RAILWAY TEST COMMISSION 



sisted essentially of a "T" shaped lever extending from the 
trolley support toward the front of the car. At the end of this 
lever are seen cast-iron weights for producing the proper amount 
of counterweighting. 




Fig. 195, — Interior View of Car "Louisiana," Looliing from the Center of the 
Car and Looliing Forward. 

The Calibration of the Dynamometers. 

A very considerable amount of time and attention was given 
to the general question of the calibration of the weighing 
mechanism. Various schemes for calibration were considered, 
and the one finally adopted is described below. 

It was decided that the most direct and reliable calibration 
would be obtained by means of Imown pressures exerted directly 



THE TEST CAR ['LOUISIANA" bdi 

Upon the vestibule and car body. The most convenient method 
of obtaining variable direct pressures of this nature was by- 
means of a large bell-crank lever. Fig. 176 shows this lever 
in position for calibration with the "Flat" vestibule, which was 
used in Test No. 60. This lever had a short arm of 18 in. 
and a long arm of 9 ft. Three weights were employed in the 
calibration. These weights consisted of pinion wheels taken 
from motor armatures, and weighing approximately 50 lbs. 
apiece. The exact weight of each of these pinions was carefully 
determined, and the pressure exerted upon the vestibule was 
varied by using 1, 2, or 3 weights, and by varying the point 
of suspensions on the long lever arm. Knowing the weight 
suspended and the length of the lever arms, the actual pres- 
sure exerted upon the vestibule could be readily determined. 
As the vestibule re-acted against the car body, and as the sup- 
port for the bell-crank lever was fixed relative to the flat car, 
the calibration of the car body dynamiometer was carried on 
simultaneously with that of the vestibule. 

As half of the dynamometer readings taken during the tests 
were tension readings, it was necessary to cahbrate the dyna- 
mometer for tension as well as for pressure. This was done by 
reversing the bell-crank lever and lowering the supporting frame- 
work, changing some of the necessary supports, and by con- 
necting the short arm of the bell-crank lever to the vestibule 
by means of a light steel cable. The tension readings were 
made by weighing the long lever arm as in taking the pressure 
measurements. In all cases the compression or tension was 
exerted at a point close to the center of the movable vestibule. 
Both high and low values of the readings were obtained, and 
the average used so that frictional effects were eliminated. 

Calibration data were obtained for the flat movable vestibule, 
and also for the standard movable vestibule, w^hen hanging 
in position. This was done in order to determine any differ- 
ence in the reading of the dynamometer in the two cases, with 
a given pressure exerted by the calibrating lever. It was 
thought that some difference might exist in the two cases, due 



632 ELECTRIC RAILWAY TiJST COMMISSION 

to the fact that one of the vestibules was very much heavier 
than the other, and that, consequently, more frictional effects 
might enter. This difference was found to be slight, and an 
average of the two calibrations was used in working up the 
results of the various tests. 

In the above calibrations a perfectly level track was selected, 
an engineer's level being used in placing the car in position. 
The level of the fiat car floor was carefully determined, measure- 
ments being made at each of the four corners of the car. 

As a slight difference in the level of the flat car floor was ob- 
served even under these conditions, the car was turned around 
after the calibration data were obtained, and the calibration 
was repeated with the car in a reverse position. 

THE CALIBRATIONS OF THE DYNAMOMETER DIALS. 

Very shortly after the dynamometer was first placed in posi- 
tion, it was observed that a given change of reading on the dial 
did not correspond with the change of weight on the scale-pan. 
While this difference was not very nmch in the dynamometer 
used with the movable vestibule, it was quite different, espe- 
cially for large dial readings, in the case of the car body dyna- 
mometer. In general, for a given reading, the dial indication 
was considerably less than that of the corresponding weight on 
the scale-pan. This effect was probably due in a large measure 
to the fact that some considerable friction and loss of motion 
was incident to the operation of the dynamometers, especially 
that showing the car body readings. 

In order to find the weight on the scale-pan equivalent to a 
given dial reading, a large number of observations was made 
on both dynamometers throughout the entire series of tests. 
These readings were made at the time when the zero readings 
were taken, and the general method employed follows. 

As already stated, both the vestibule and the car body dyna- 
mometers were counterweighted. By changing the weights on 
the scale-pan, the dial readings could be adjusted to any desired 
value. By proceeding in this way, the actual weight on the 



THE TEST CAR ['LOUISIANA." 533 

scale-pan for a given change in the dial reading at a given part 
of the scale, was obtained. A curve was then plotted for the 
djTiamometer, showing the actual weight on the scale-pan cor- 
responding to a given dial reading. These curves were em- 
ployed in the reduction of the djniamometer dial data to the 
corresponding weight on the scale-pan. 

THE CALIBRATION CURVES. 

From the calibration data obtained in the manner described 
above, a large number of data was obtained showing the rela- 
tion between the weight on the scale-pan of each dynamometer 
and the pressure (or tension), in pounds, exerted upon the weight- 
ing mechanism. In obtaining this data it was necessary to 
reduce the dial readings to data showing the equivalent weight 
on the scale-pan. Curves were constructed from the calibra- 
tion data, showing the relation between the equivalent scale- 
pan readings of the dynamometer in each case, and the actual 
pressure exerted. These curves were used in interpreting the 
results of the various tests. A difference was found between 
the compression and the tension data. Different curves were 
used for the two general conditions. 



CHAPTER XVI. 



AIR RESISTANCE TESTS. 



Objects of the Tests. 
While the primary object of the tests of Chapter XIV, was 
to determine the total train resistance of interurban cars when 
running at various speeds, the principal object of the tests of 
the present chapter was to separate the head resistance, the rear 
suction and the side and roof resistance, due to air pressure 
from the total train resistance. Another important object was 
the determination of the effect of varying the forms of the front 
and rear vestibules, upon the various air resistance factors. 



Synopsis of Results. 
Table LXXIII gives briefly the general results of the air 
resistance tests which are discussed in this chapter. 



Table LXXIII. 



Synopsis of Results of Air Resistance Tests. Vestibule 
Data. 



Type of Movable 

Vestibule. 



Parabolic Wedge 
Parabola. . . . 
Standard . . . 

Flat 

Parabola. . . . 
Parabolic Wedge 

Flat 

Standard . . . 



Air Resistance in Lbs. per 

Sq. Ft. at Various Speeds 

IN Miles per Hour. 



20 



0.39 
0.50 
0.33 
1.40 
0.08 
0.19 
0.14 
0.13 



30 



0.48 
0.63 
0.90 
2.20 
0.09 
0.20 
0.17 
0.22 



40 



0.73 
0.90 
1.98 
3.56 
0.11 
0.23 
0.20 
0.40 



50 



1.37 
1.60 
3.18 
5.60 
0.15 
0.28 
0.37 
0.70 



60 



2.10 
2.50 
4.53 
8.20 
0.24 
0.45 
0.50 
1.04 



Remarks, 



Head Pressure 
Head Pressure 
Head Pressure 
Head Pressure 
Rear Suction 
Rear Suction 
Rear Suction 
Rear Suction 



Note. — The above values are taken from the curves of Figs. 199, 200, 201, and 2C2. 
The power data corresponding to these conditions are given in Table LXXXV. 

Car Body Data. 
The results of all tests show an average speed of 36.4 miles per hour and a total pres- 
sure of 97.6 pounds. 

534 



AIR RESISTANCE TESTS 



635 



General Conditions of the Tests. 

The tests were conducted between Noblesville and Carmel, 
Indiana, upon the stretch of tangent track described in Chapter 
XIV, in connection with the car resistance tests. As the direc- 
tion of the car, with reference to the direction of the wind, is a 



Notlesville 



>E 




Carmel 



Fig. 196. — Direction of Test Tracfi between Noblesville and Carmel, Indiana. 



matter of considerable importance in these tests, the direction 
of the track with reference to the four points of the compass, 
was accurately determined and is shown in Fig. 196. The data 
giving the direction and velocity of the wind at 8 a.m., 12 o'clock 
noon, and 4 p.m., are shown in Table LXXIV. 

Table LXXIV. — Data Showing Direction and Velocity of Wind. For Air 

Resistance Tests. 





Hours Ending at 


. - 


Date. 


8 A.M. 


12 M. 


4. P.M. 


8 A.M. 


12 M. 


4 P.M. 




Wind Velocity. 


Wi? 


w Direction. 


Feb. 15 


8 


5 


10 


N.W. 


W. 


W. 


16 


13 


18 


18 


S.E. 


s 


s. 


17 


13 


22 


20 


s.w. 


w. 


w. 


18 


9 


5 


11 


s.w. 


s.w. 


s.w. 


19 


6 


12 


9 


s.w. 


s. 


S.E. 


20 


6 


7 


6 


s. 


s.w. 


S.W. 


21 


6 


10 


11 


s.w. 


s. 


s. 


22 


8 


8 


6 


N.W. 


N.W. 


w. 



536 



ELECTRIC RAILWAY TEST COMMISSION 



Table LXXIV. — Continued. 





Hours Ending at 


Date. 


8 A.M. 


12 m. 


4 P.M. 


8 A.M. 


12 M. 


4 P.M. 




Wind Velocity. 


Wind Direction. 


Feb. 23 

24 

25 

26 

27 

28 

Mar. 1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 


3 

12 

22 
6 

12 
6 

10 
7 
5 

14 
7 

12 
6 

10 
7 

10 
3 
8 
5 

11 
7 
4 
8 

16 

18 
4 


10 
12 
20 

7 

6 

9 
10 

6 

9 

9 

6 
15 

4 
10 . 

4 

6 

4 
10 

5 
11 

5 
13 
18 
26 
24 

8 


7 

12 

13 

6 

8 

8 

10 

7 

15 

8 

6 

14 

3 

8 

3 

11 

7 

8 

4 

12 

5 

11 

17 

22 

19 

11 


N.W. 

S.E. 

N.W. 

N.W. 

N.E. 

W. 

N.W. 

E. 

S. 

N. 

S.E. 

N.E. 

N.E. 

N. 

N.E. 

N. 

N. 

N.E. 

N. 

N.E. 

E. 

S.E. 

S. 

S. 

s. 

N.W. 


S. 

S.E. 

N.W. 

N.W. 

N.E. 

S.W. 

N. 

S. 

S.E. 

N. 

S.W. 

E. 

N.E. 

N. 

N.E. 

^.W. 

N.W. 

N. 

N. 

N.E. 

S.E. 

E. 

S. 

S.W. 

s. 

N.E. 


S.E. 

S.E. 

N.W. 

N.W. 

N.W. 

S. 

N. 

S.E. 

S. 

N.E. 

N.W. 

E. 

N.E. 

N. 

N. 

W. 

N.W. 

N. 

N. 

N.E. 

S.E. 

S.W. 

s. 
s. 
w. 

N.E. 



The tests continued from January 15, to March 16, 1905, and 
included, in all, several hundred separate and independent 
runs. There were four general series of tests, in addition to 
the preliminary or trial tests. The general conditions of each 
series, together with the schedule of rims, are given below. 



AIR RESISTANCE TESTS 



537 



Table LXXV. — Schedule of Runs for Preliminary Tests. 
Preliminary Runs with Parabolic Vestibule. 



Run. No. 


Date 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


1 


Jan. 27 


West 


West 


4 motors in series-parallel 


2 


Jan. 27 


East 


West 


2 motors in series 


3 


Jan. 27 


West 


West 


2 motors in series 


4 


Jan. 27 


East 


West 


4 motors in series-parallel 


5 


Jan. 27 


West 


West 


2 motors in parallel 


6 


Jan. 27 


East 


West 


2 motors in series 


7 


Jan. 27 


West 


West 


4 motors in parallel 


8 


Jan. 27 


East 


West 


4 motors in parallel 


9 


Jan. 27 


West 


West 


4 motors in parallel 


10 


Jan. 27 


East 


West 


4 motors in parallel 


11 


Jan. 27 


West 


West 


4 motors in parallel 


12 


Jan. 27 


East 


West 


4 motors in parallel 


13 


Jan. 27 


West 


West 


1 motor in parallel 


14 


Jan. 27 


East 


West 


4 motors in series-parallel 


15 


Jan. 27 


West 


West 


3 motors in series-parallel 


16 


Jan. 27 


East 


West 


2 motors in series-parallel 


17 


Jan. 27 


West 


West 


4 motors in series-parallel 


18 


Jan. 27 


East 


West 


4 motors in series-parallel 


19 


Jan. 28 


West 


East 


4 motors in parallel 


20 


Jan. 28 


East 


East 


4 motors in parallel 


21 


Jan. 28 


West 


East 


4 motors in parallel 


22 


Jan. 28 


East 


East 


4 motors in parallel 


23 


Jan. 28 


West 


East 


4 motors in series-parallel 


24 


Jan. 28 


East 


East 


2 motors in series 


25 


Jan. 28 


West 


■ East 


2 motors in parallel 


26 


Jan. 28 


East 


East 


4 motors in series-parallel 



Preliminary Tests. 

A number of trial runs were made on January 27 and 28, 
in order to test the equipment in general. The car was fitted 
with the parabolic movable vestibule and the standard fixed 
vestibule, as shown in Fig. 172. The general conditions were 
the same as in Test No. 59, except that the car body coun- 
terweight had not yet been installed. These tests were made 
for the purpose of testing out the equipment in general and the 
data were not worked up into final form. Twenty-six runs in 
all were made and the schedule of these runs is given in 
Table LXXV, 



538 



ELECTRIC RAILWAY TEST COMMISSION 



TEST NO. 58, PARABOLIC WEDGE VESTIBULE. 

After the preliminary investigations, the car was run back 
to Anderson, where the car body counterweight was constructed 
and installed. The parabolic shaped vestibule was also built 
out in the parabolic wedge form at this time, as shown in Fig. 
174. Considerable difficulty was experienced in this series of 
tests, with the dynamometer, especially that used in connection 
with the car body readings. The oil cylinder buffing device 
was experimented with under various conditions of operation 
before satisfactory dynamometer readings were obtained. One 
hundred and two independent runs were made in this series of 
tests but many of them were repetitions under slightly different 
conditions. Many of the runs were made in an endeavor to 
obtain higher speeds by means of the use of resistance grids 
connected across the motor fields. The schedule of these runs 
is given in Table LXXVI. 

Table LXXVI. — Schedule of Runs with Parabolic Wedge Vestibule. 





Date, 


Car 


Vestibule 




Run No. 


1905. 


Going. 


Pointed. 


Motor Connections. 


1 


Feb. 




West 


East 


4 motors in series-parallel. 


2 


Feb. 




East 


East 


4 motors in series-parallel. 


3 


Feb. 




West 


East 


Motors 1 and 2 in series. 


4 


Feb. 




East 


East 


Motors 1 and 2 in series. 


5 


Feb. 




West 


East 


4 motors in series. Grids on 
motors. 


6 


Feb. 




East 


East 


4 motors in series-parallel. 
Grids on motors. 


7 


Feb. 




West 


West 


4 motors in series-parallel. 


8 


Feb. 




East 


West 


4 motors, series-parallel. 


9 


Feb. 




West 


West 


Nos. 1 and 2 in series. 


10 


Feb. 




East 


West 


Motors 1 and 2 in full series. 


11 


Feb. 




West 


West 


4 motors full series-parallel, 
grids on motors. 


12 


Feb. 




East 


West 


4 motors full series-parallel, 
grids on motors. 


13 


Feb. 




West 


West 


4 motors full parallel. 


14 


Feb. 




East 


West 


4 motors full parallel. 


15 


Feb. 




West 


West 


4 motors parallel, grids on 
motors. 


16 


Feb. 




East 


West 


4 motors full parallel, grids on 
motors. 


17 


Feb. 




West 


West 


4 motors, full parallel, grids on 
motors. 



AIR RESISTANCE TESTS 
Table LXXVI. — Continued. 



539 



Run No. 


Date, 
1905. . 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


18 


Feb. 11 


East 


West 


4 motors, full parallel, grids 
on motors. 


19 


Feb. 14 


West 


West 


4 motors, full parallel. 


20 


Feb. 14 


East 


AYest 


4 motors, full parallel. 


21 


Feb. 14 


West 


West 


4 motors, full parallel. 


22 


Feb. 14 


East 


West 


4 motors, full parallel. 


23 


Feb. 14 


West 


West 


4 motors, full parallel. 


24 


Feb. 14 


East 


West 


4 motors, full parallel. 


25 


Feb. 14 


West 


West 


4 motors, full parallel. 


26 


Feb. 14 


East 


West 


4 motors, full parallel. 


27 


Feb. 14 


West 


West 


4 motors, parallel. 


28 


Feb. 14 


East 


West 


4 motors, full parallel. 


29 


Feb. 15 


West 


East 


4 motors, full parallel. 


30 


Feb. 15 


East 


East 


4 motors, full parallel. 


31 


Feb. 15 


West 


East 


4 motors, full parallel, grids 
on motors. 


32 


Feb. 15 


East 


East 


4 motors, full parallel, grids 
on motors. 


33 


Feb. 15 


West 


East 


4 motors, full parallel, grids 
on motors. 


34 


Feb. 15 


East 


East 


4 motors, full parallel, grids 
on motors. 


35 


Feb. 15 


West 


East 


2 motors, 1 and 4 in series, 
run made at a slow speed 
dowTi line to determine 
zeros at various points. 
Wind pressure slight. 


36 


Feb. 15 


East 


East 


4 motors, parallel, grids on 
motors. 


37 


Feb. 15 


West 


East 


4 motors, parallel, grids on 
motors. 


38 


Feb. 15 


East 


East 


4 motors, parallel, grids on 
motors. 


39 


Feb. 15 


West 


East 


4 motors, full parallel, grids 
on motors. 


40 


Feb. 15 


East 


East 


4 motors, parallel, grids on 
motors. 


41 


Feb. 16 


West 


East 


1 and 4 full series, motor oil in 
cylinder pumped up full. 


42 


Feb. 16 


East 


East 


2 motors (1 and 4) full series. 


43 


Feb. 16 


West 


East 


4 motors, full series-parallel. 


44 


Feb. 16 


East 


East 


4 motors, full series-parallel. 


45 


Feb. 16 


West 


East 


1 and 4 motors in series, slow 
run to test d^-namometer. 


46 


Feb. 16 


East 


East 


1 and 4 series, slow run to test 
dATiamometer. 


47 


Feb. 16 


West 


East 


4 motors, full parallel. 


48 


Feb. 16 


East 


East 


4 motors, full parallel. 


49 


Feb. 16 


West 


East 


Motors 1 and 4, full parallel. 


50 


. Feb. 16 


East 


East 


2 motors, 1 and 4, full parallel. 


51 


Feb. 16 


West 


East 


4 motors, full parallel. 



540 ELECTRIC RAILWAY TEST COMMISSION 

Table LXXVI. — Continued. 



Run No. 


Date, 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


52 


Feb. 16 


East 


East 


4 motors, full parallel, grids 
on 8 sections. 


53 


Feb. 16 


West 


East 


4 motors, full parallel. 


54 


Feb. 16 


East 


East 


4 motors, full parallel, grids 
on motors, 16 sections in- 
stead of 18. 


55 


Feb. 16 


West 


East 


4 motors, full parallel, 14 sec- 
tions of grids on motors. 


56 


Feb. 16 


East 


East 


4 motors, full parallel, 14 sec- 
tions of grids on motors. 


57 


Feb. 16 


West 


East 


4 motors, full parallel, 12 sec- 
tions of grids on motors 


58 


Feb. 16 


East 


East 


4 motors, full parallel, 12 sec- 
tions of grids on motors. 


59 


Feb. 16 


West 


East 


4 motors, full parallel, 10 sec- 
tions of grids on motors. 


60 


Feb. 16 


East 


East 


4 motors, full parallel, 10 sec- 
tions grids on motors. 


61 


Feb. 17 


West 


West 


1 and 4, full series. 


62 


Feb. 17 


East 


West 


1 and 4 in full series. 


63 


Feb. 17 


West 


West 


1 and 4 in series. 


64 


Feb. 17 


East 


West 


1 and 4 motors in series. 


65 


Feb. 17 


West 


West 


4 motors, full series-parallel. 


66 


Feb. 17 


East 


West 


4 motors, full series-parallel. 


67 


Feb. 17 


West 


West 


4 motors, full parallel. 


68 


Feb. 17 


East 


West 


4 motors, full parallel. 


69 


Feb. 17 


West 


West 


4 motors, full parallel. 


70 


Feb. 17 


East 


West 


4 motors, full parallel, 20 sec- 
tions grids on motors. 


71 


Feb. 18 


West 


West 


4 motors, full parallel, 16 sec- 
tions grids on motors. 


72 


Feb. 18 


East 


West 


4 motors, full parallel, 16 sec- 
tions grids on motors. 


73 


Feb. 18 


West 


West 


4 motors, full parallel. 


74 


Feb. 18 


East 


West 


4 motors, full parallel, 12 sec- 
tions grids on motors. 


75 


Feb. 18 


West 


West 


4 motors, full parallel, 8 sec- 
tions grids on motors. 


76 


Feb. 18 


East 


West 


4 motors, full parallel, 8 sec- 
tions grids on motors. 


77 


Feb. 18 


West 


West 


4 motors, full parallel, 6 sec- 
tions grids on motors. 


78 


Feb. 18 


East 


West 


4 motors, full parallel, 6 sec- 
tions grids on motors. 


79 


Feb. 18 


West 


West 


4 motors, full parallel, 4 sec- 
tions grids on motors. 


80 


Feb. 18 


East 


West 


4 motors, full parallel, 4 sec- 
tion grids on motors. 


81 


Feb. 18 


West 


East 


4 motors, full parallel, 4 sec- 
tions grids on motors. 


82 


Feb. 18 


East 


East 


4 motors, full parallel, 4 sec- 










tions grids on motors. 



AIR RESISTANCE TESTS 



541 



Table LXXVI. — Concluded. 



Run No. 


Date, 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


83 


Feb. 18 


West 


East 


84 


Feb. 18 


East 


East 


85 


Feb. 18 


West 


East 


86 


Feb. 18 


East 


East 


87 


Feb. 20 


West 


East 


88 


Feb. 20 


East 


East 


89 


Feb. 20 


West 


East 


90 


Feb. 20 


East 


East 


91 


Feb. 20 


West 


East 


92 


Feb. 20 


East 


East 


93 
94 
95 


Feb. 20 
Feb. 20 
Feb. 20 


West 
East 
West 


East 
East 
West 


96 


Feb. 20 


East 


West 


97 


Feb. 20 


West 


West 


98 


Feb. 20 


East 


West 


99 


Feb. 20 


West 


West 


100 


Feb. 20 


East 


West 


101 


Feb. 20 


West 


West 


102 


Feb. 20 


East 


West 



Motor Connections. 

4 motors, full parallel, 6 grids 
on motors. 

4 motors, full parallel, 6 sec- 
tions grids on motors. 

4 motors, full parallel, 8 sec- 
tion grids on motors. 

4 motors, full parallel, 8 sec- 
tions grids on motors. 

4 motors, full parallel. No 
grids on motors. 

4 motors full parallel. No 
grids on motors. 

4 motors, full parallel, 16 sec- 
tion grids on motors. 

4 motors, full parallel, 16 sec- 
tion grids on motors. 

4 rnotors, full parallel, 10 
grids on motors. 

4 motors, full parallel, 4 sec- 
tions grids on motors. 

4 motors, full parallel. 

4 motors, full parallel, 

4 motors, full parallel. No 
grids on motors. 

4 motors, full parallel. No 
grids on motors. 

4 motors, full parallel, 4 grids 
on motors. 

4 motors, full parallel, 4 grids 
on motors. 

4 motors, full parallel, 10 sec- 
tion grids on motors. 

4 motors, full parallel, 10 sec- 
tion grids on motors. 

4 motors, full parallel, 16 sec- 
tion grids on motors. 

4 motors, full parallel, 16 sec- 
tion of grids on motors. 



TEST NC. 59, PARABOLA VESTIBULE. 

After the tests with the parabolic wedge movable vestibule 
were completed, the car was run back to the substation at 
Noblesville and the wedge structure was taken down, leaving 
the movable vestibule in its original parabolic form, as shown 
in Fig. 172. Thirty-eight runs were then made, the schedule 
of tests being as shown in Table LXXVIL 



Bi2 



ELECTRIC RAILWAY TEST COMMISSlO^i 



Table LXXVII. 


— Schedule 


of Runs. 


With Parabolic Vestibule. 


Run No. 


Date, 
1905. 


Car 
Going. 


v^estibule 
Pointed. 


Motor Connections. 


1 


Feb. 21 


West 


East 


4 motors in parallel. No 
grids on motors. 


2 


Feb. 21 


East 


West 


4 motors in parallel. No 
grids on motors. 


3 


Feb. 21 


West 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


4 


Feb. 21 


East 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


5 


Feb. 21 


West 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


6 


Feb. 21 


East 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


7 


Feb. 21 


West 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


8 


Feb. 21 


East 


West 


4 motors in parallel, 10 sec- 
tions of grids on motors. 


9 


Feb. 21 


West 


West 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


10 


Feb. 21 


East 


West 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


11 


Feb. 21 


West 


East 


4 motors in parallel. No 
grids on motors. 


12 


Feb. 21 


East 


East 


4 motors in parallel. No 
grids on motors. 


13 


Feb. 21 


West 


East 


4 motors in parallel, 4 sections 
of grids on motors. 


14 


Feb. 21 


East 


East 


4 motors in parallel, 4 sections 
of grids on motors. 


15 


Feb. 21 


West 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


16 


Feb. 21 


East 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


17 


Feb. 21 


West 


East 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


18 


Feb. 21 


East 


East 


4 motors in parallel, 10 sec- 
tions of grids on motors. 


19 


Feb. 21 


West 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


20 


Feb. 21 


East 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


21 


Feb. 21 


AVest 


East 


4 motors. 


22 


Feb. 21 


East 


East 


4 motors. 


23 


Feb. 22 


West 


East 


2 motors in parallel. No 
grids on motors. 


24 


Feb. 22 


East 


East 


2 motors in parallel. No 
grids on motors. 


25 


Feb. 22 


West 


East 


2 motors in series. 


26 


Feb. 22 


East 


East 


2 motors in series. 


27 


Feb. 22 


West 


East 


4 motors in series-parallel. 


28 


Feb. 22 


East 


East 


4 motors in series. 


29 


Feb. 22 


West 


East 


2 motors in series. 



AIR RESISTANCE TESTS 



543 



Table LXXVII. — Continued. 



Run No. 


Date, 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


30 


Feb. 22 


East 


East 


2 motors in series. 


31 


Feb. 22 


West 


West 


2 motors in series. 


32 


Feb. 22 


East 


West 


2 motors in series. 


33 


Feb. 22 


West 


West 


4 motors in series. 


34 


Feb. 22 


East 


West 


4 motors in series. 


35 


Feb. 22 


West 


West 


2 motors in parallel. 


36 


Feb. 22 


East 


West 


2 motors in parallel. 


37 


Feb. 22 


West 


West 


2 motors in series. 


38 


Feb. 22 


East 


West 


2 motors in series. 



TEST NO. 60, FLAT VESTIBULE. 

Upon the completion of the tests with the parabohc vestibule, 
the car was run back to Anderson and the parabolic movable 
vestibule was taken off, the "flat" vestibule being put in its 
place. The car was then equipped as shown in Fig. 176, 
except that the calibrating lever was not in position at the 
time the tests were made. The flat vestibule tests included 
forty runs, as shown in Table LXXVIII. 



Table LXXVIII. — Schedule of Runs 


. With Flat Vestibule. 




Date, 


Car 


Vestibule 




Run No. 


1905. 


Going. 


Pointed. 


Motor Connections. 


1 


Feb. 25 


West 


East 


2 motors 


m parallel. 


2 


Feb. 25 


East 


East 


2 motors 


in parallel. 


3 


Feb. 25 


West 


East 


4 motors 


in series-parallel. 


4 


Feb. 25 


East 


East 


4 motors 


m series-parallel. 


5 


Feb. 25 


West 


East 


4 motors 


m parallel. 


6 


Feb. 25 


East 


East 


4 motors 


m parallel. 


7 


Feb. 25 


West 


East 


4 motors 


in parallel. 


8 


Feb. 25 


East 


East 


4 motors 


m parallel. 


9 


Feb. 27 


West 


East 


2 motors 


m parallel. 


10 


Feb. 27 


East 


East 


2 motors 


m parallel. 


11 


Feb. 27 


West 


East 


2 motors 


m series. 


12 


Feb. 27 


East 


East 


2 motors 


in series. 


13 


Feb. 27 


West 


East 


4 motors 


in series-parallel. 


14 


Feb. 27 


East 


East 


4 motors 


m series-parallel. 


15 


Feb. 27 


W^est 


West 


4 motors 


in series-parallel. 


16 


Feb. 27 


East 


West 


4 motors 


m series-parallel. 


17 


Feb. 27 


West 


West 


2 motors in series. 



644 ELECTRIC RAILWAY TEST COMMISSION 

Table LXXVIII. — Continued. 



Run No. 


Date, 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


18 


Feb. 


27 


East 


West 


2 motors in series. 


19 


Feb. 


27 


West 


West 


2 motors in series. 


20 


Feb. 


27 


East 


West 


2 motors in series. 


21 


Feb. 


27 


West 


West 


2 motors in parallel. 


22 


Feb. 


27 


East 


West 


2 motors in parallel. 


. 23 


Feb. 


28 


West 


West 


4 motors in parallel. 


24 


Feb. 


28 


East 


West 


4 motors in parallel. 


25 


Feb. 


28 


West 


West 


4 motors in parallel. 


26 


Feb. 


28 


East 


West 


4 motors in parallel. 


27 


Feb. 


28 


West 


West 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


28 


Feb. 


28 


East 


West 


4 motors in parallel. 


29 


Feb. 


28 


West 


West 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


30 


Feb. 


28 


East 


West 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


31 


Feb. 


28 


West 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


32 


Feb. 


28 


East 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


33 


Feb. 


28 


West 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


34 


Feb. 


28 


East 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


35 


Feb. 


28 


West 


East 


4 motors in parallel, 12 sec- 
tions of grids on motors. 


36 


Feb. 


28 


East 


East 


4 motors in parallel, 12 sec- 
tions of grids on motors. 


37 


Feb. 


28 


West 


East 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


38 


Feb. 


28 


East 


East 


4 motors in parallel, 4 sec- 
tions of grids on motors. 


39 


Feb. 


28 


West 


East 


4 motors in parallel, no grids 
on motors. 


40 


Feb. 


28 


East 


East 


4 motors in parallel, no 
grids on motors. 



TEST NO. 61, STANDARD VESTIBULE. 

The car was run back to the Anderson yards when Test No. 
60 was completed and a series of cahbration experiments was 
made, as discussed in Chapter XV. The "flat" vestibule was 
then taken off and the standard vestibule was removed from 
the rear of the car and mounted as the movable vestibule on 
the front, there being no rear vestibule in these tests. The 
experiments with the standard movable vestibule included 
thirty-six runs, as shown in Table LXXIX. 



AIR RESISTANCE TESTS 



545 



Table LXXIX. 


— Schedule 


of Runs. 


With Standard Vestibule. 


Run No. 


Date, 
1905. 


Car 
Going. 


Vestibule 
Pointed. 


Motor Connections. 


1 


Mar. 


7 


West 


East 


2 motors 


m series. 


2 


Mar. 


7 


East 


East 


2 motors 


in series. 


3 


Mar. 


7 


West 


East 


4 motors 


m series-parallel. 


4 


Mar. 


7 


East 


East 


4 motors 


n series-parallel. 


5 


Mar. 


7 


West 


East 


2 motors 


in series. 


6 


Mar. 


7 


East 


East 


2 motors 


in series. 


7 


Mar. 


7 


West 


East 


2 motors 


n parallel. 


8 


Mar. 


7 


East 


East 


2 motors 


n parallel. 


9 


Mar. 


7 


West 


West 


4 motors 


n series-parallel. 


10 


Mar. 


7 


East 


West 


4 motors 


n series-parallel. 


11 


Mar. 


7 


West 


West 


2 motors 


n series. 


12 


Mar. 


7 


East 


West 


2 motors 


n series. 


13 


Mar. 


7 


West 


West 


2 motors 


n parallel. 


14 


Mar. 


7 


East 


West 


2 motors 


n parallel. 


15 


Mar. 


7 


West 


West 


2 motors 


n series. 


16 


Mar. 


7 


East 


West 


2 motors 


n series. 


17 


Mar. 


8 


West 


West 


4 motors i 


m parallel. 


18 


Mar. 


8 


East 


West 


4 motors in parallel. 


19 


Mar. 


8 


West 


West 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


20 


Mar. 


8 


East 


West 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


21 


Mar. 


8 


West 


West 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


22 


Mar. 


8 


East 


West 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


23 


Mar. 


8 


West 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


24 


Mar. 


8 


East 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


25 


Mar. 


8 


West 


East 


4 motors in parallel. No 
grids on motors. 


26 


Mar. 


8 


East 


East 


4 motors in parallel. No 
grids on motors. 


27 


Mar. 


10 


West 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


28 


Mar. 


10 


East 


East 


4 motors in parallel, 20 sec- 
tions of grids on motors. 


29 


Mar. 


10 


West 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


30 


Mar. 


10 


East 


East 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


31 


Mar. 


10 


West 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


32 


Mar. 


10 


East 


West 


4 motors in parallel, 16 sec- 
tions of grids on motors. 


33 


Mar. 


10 


West 


West 


4 motors in parallel, 12 sec- 
tions of grids on motors. 


34 


Mar. 


10 


East 


West 


4 motors in parallel, 12 sec- 
tions of grids on motors. 


35 


Mar. 


10 


West 


West 


4 motors in .parallel, 8 sec- 
tions of grids on motors. 


36 


Mar. 


10 


East 


West 


4 motors in parallel, 8 sec- 
tions of grids on motors. 



546 ELECTRIC RAILWAY TEST COMMISSION 

General Description of the Tests. 

The general plan of the tests consisted in careful determina- 
tions of the speed, the pressure upon the vestibule, and the 
pressure upon the car body as a whole. As the mechanical 
devices for making these measurements have already been 
described in Chapter XV, in the present chapter it will be un- 
necessary to discuss more than the plan of conducting the tests. 
Before starting a run, the general speed conditions were decided 
upon and the car was operated under such conditions of motor 
connections as to produce the desired results. The highest 
speeds were obtained by connecting the four motors in parallel 
and shunting their fields. In running the car at the slowest 
speeds, two motors were used, connected in series, with the 
extra resistance grids also inserted in the circuit. The General 
Electric Company's ammeter was used to graphically record the 
current, and its accompanying time marking device, the five- 
second intervals. 

The time a certain part of the car passed a given pole was 
also recorded on the graphical ammeter record. The method 
used to accomplish this was somewhat similar to that used, and 
described in Chapters IV and XIV. 

In addition to the time and distance records mentioned above, 
the speed was obtained directly by taking readings every five 
seconds of the indications of a low reading voltmeter attached 
to the magneto generator driven from the car axle, as described 
in Chapter IV. This device w^as calibrated by direct compari- 
sons with the time and distance data. 

The line pressure was obtained by means of voltmeter read- 
ings taken every five seconds and the graphical record of current 
was checked by similar readings taken on an indicating ammeter. 
The vestibule and car-body air pressure measurements were 
made by means of readings of the dynamometers, these readings 
being also taken at five-second intervals. 

In order to secure uniformity and accuracy in recording the 
results of the various measurements, a " Data Sheet " of stan- 



Air resistance tests 



547 



Sheet No 

ELECTRIC RAILWAY TEST COMMISSION. 

AIR RESISTANCE TESTS. 



Test Run No 

Da 

Date Time of 

Car qoinq Vestihul 










ta 
start 


e vointeA 






1 






26 






51 






76 






2 






27 






52 






77 






3 






28 






53 






78 






4 






29 






54 






79 






5 






30 






55 






80 






6 






31 






56 






81 






7 






32 






57 






82 






8 






33 






58 






83 






9 






34 






59 






84 






10 






35 






60 






85 






11 






36 






61 






86 






12 






37 






62 






87 






13 






38 






63 






88 






14 






39 






64 






89 






15 






40 






65 






90 






16 






41 






66 






91 






17 






42 






67 






92 






18 






43 






68 






93 






19 






44 






69 






94 






20 






45 






70 






95 






21 






46 






71 






96 






22 






47 






72 






97 






23 






48 






73 






98 






24 






49 






74 






99 






25 






50 






75 






100 






h 


lemarki 


f 


'ig. 19 


7. — Data 


Sheet f 


or Air 


Resistcui 


ce Tests 




. Observ 


er. 



548 ELECTRIC RAILWAY TEST COMMISSION 

dard letter size, was prepared, as shown in Fig. 197. Each 
observer in the car was provided with a supply of these 
sheets which contained blank spaces opposite numbers from 
1 to 100. 

The Director of the test determined at what part of a run the 
measurements should be recorded and he called out the number 
opposite which each reading should be set down. A bell signal 
was given every five seconds by the chronometer used in con- 
nection with the recording ammeter and pole record, and this 
signal was used to determine the exact instant at which to call 
off the reading number. The Director was stationed opposite 
a clock equipped with a second hand, so that, in case of the 
failure of the bell to ring at the proper time, he could give his 
signal from the clock. Immediately after the close of each run 
the record sheets for that run were assembled and bound together 
into a book, with a cover similar to that shown in Fig. 198. By 
thus binding together the data sheets for each run, it was possible 
to avoid any confusion in the records and any danger of losing 
or mislaying the sheets was eliminated. 



ORIGINAL MEASUREMENTS. 

Speed Measurements. 

As in the preceding tests, two separate methods of determin- 
ing the speed were employed. The small generator belted to the 
car axle, with its field magnet excited from a storage battery in 
circuit with the field of the recording ammeter, was used to 
indicate the relative speed at different parts of a run. In order 
to determine the average speed with great exactness, the instants 
of passing certain poles were accurately recorded on the chrono- 
graph record. As a check on this determination, the average 
reading of the speed generator was determined and corrected by 
calibration. The readings of the speed generator voltmeter, as 
well as those of all other instruments, were made every five 
seconds. 



AIR RESISTANCE TESTS 549 

Sheet No 

ELECTRIC RAILWAY TEST COMMISSION. 

Ain RESISTANCE TESTS. 

General Data. 

Date 190 

Test Run No 

Car Going Vestibule Pointed 

Time of Start Time of Stop 

Type of Movable Vestibule 

Line Pressure at Start (Controller off) Volts 

Motor Connections 

Switchboard Connections 

Switches Open 

Weather Temperature '=C. 

Condition of Track ., 

East Anemometer miles West Anemometer miles 

East Weather Vane West Weather Vane 

E.un between Pole No and Pole No 

Total Distance Run miles 

Duration of Run minutes seconds 

Averages. 

Velocity of Wind miles per hour 

Speed miles per hour Direction of Wind 

Total Motor Current Amperes Total Motor Pressure Volts 

Vestibule Pressure lbs. Car Body Pressure lbs. 

Vestibule Power K. W. Car Body Power K. W. 



Total Power Consumed K. W. 

Ratio of Power Consumed by Car Body to Total Power ^ Per cent 

Fig. 198. — General Data Sheet for Air Resistance Tests. 



550 ELECTRIC RAILWAY TEST COMMISSION 

Air Pressure Measurements. 

Records were made of the indications of the car body and 
vestibule dynamometers, the observers noting the weight on 
the scale pan and the reading on the dial for each case. In 
order to determine the zero values of the readings of each of the 
dynamometers, the car was placed on a level stretch of track and 
a series of zero readings was taken with various weights on the 
scale -pan, the corresponding readings on the dials being noted. 

Occasionally, a series of zero readings was taken on several 
stretches of track, either level or of known grade, but generally 
the zeros were taken at one point on the test track, and wherever 
possible they were taken every two runs. 

Electrical Measurements. . 

The graphical record of current was made on the General 
Electric recording ammeter which was checked from time to 
time by readings of a Weston indicating ammeter. The electrical 
pressure was read every five seconds and the power was deter- 
mined from the readings of e.m.f. and current. 

Other Measurements. 

An anemometer was placed at each end of the test track, 
mounted at the top of a post as nearly as possible on a level 
with the center of the vestibule. A wind vane was mounted 
under each anemometer. The anemometers were loaned for this 
purpose by Messrs. Queen and Co. Readings of the wind vanes 
and of the anemometers were made at the end of each trip, 
and these data were later checked by the records of the United 
States Weather Bureau at Indianapolis. 

A spirit level was constructed for the purpose of determining 
the exact level of the car. This level consisted of two vertical 
glass tubes three feet in height, provided with verniers and 
scales, one being located near the front corner post of the car 
and the other near the rear. They were connected by a small 
steel tube and, at the points of contact between the glass and 
the steel tubes, small diaphragms were inserted with apertures 



AIR RESISTANCE TESTS 551 

adjusted to absorb the vibrations of the columns. This spirit 
level was not used when the car was in motion but it was read 
occasionally to check the grades as given by the survey of the 
road. 

WORKING UP THE RESULTS. 

In working up the results the first step was to select, from the 
entire series of tests, such a number of typical runs as could be 
studied in the time at the disposal of the Executive Committee. 
It was finally decided to take a total of sixty-four rims, sixteen 
for each type of movable vestibule. In eight runs of each set, 
the car was going in the direction in which the movable vesti- 
bule was pointed, while in the remaining eight runs of the set 
the movable vestibule was at the rear of the car. These runs 
were so selected as to give a variety of speeds sufficient to per- 
mit the plotting of the resistance curves. 

In preparing the results of the tests for study, the various 
sets of data contained in the record books were corrected by 
caUbration and the results were entered upon a series of forms 
ruled and printed for the purpose. The original intention, 
which was partly carried out, was to correct and enter upon 
these forms every individual measurement made. It was found, 
however, on account of the enormous number of calculations 
necessary to do this completely (involving upwards of a half 
million calculations and entries), that this was quite out of the 
question in the time available. Furthermore, the limits of the 
Report do not permit of exhibiting this matter in such complete 
form. It was therefore decided to summarize the results of 
typically selected runs. 

The Vestibule Data. 

The vestibule air pressure data were obtained directly by 
means of the dynamometer constructed for that purpose. It 
was necessary to interpret these data, and this was accomplished 
by means of the calibrations and zero readings mentioned in the 
present chapter and also in Chapter XV, 



552 ELECTRIC RAILWAY TEST COMMISSION 

The dynamometer readings showing the air pressure on the 
front vestibules were quite large in numerical value, especially 
at the higher speeds, and good results were obtained. The 
suction data for the rear vestibules were much lower in value 
and the results, while fairly consistent, are not as accurate as 
are those for the pressures on the front vestibules at various 
speeds. It is to be remembered in this connection, however, 
that, because of their greater numerical value, the latter data 
are of much greater importance than the former. 

The Car Body Data. 

The car body dynamometer indicated the total air resistance, 
including the pressure on the front vestibule and the suction on 
the rear vestibule. For the purpose of obtaining an average 
value of the surface friction on the sides and roof, the following 
plan was adopted. The head pressure and the suction for the 
particular form of vestibule used in a given run, were determined 
for any given speed from the air pressure curves for the vesti- 
bule. These air resistance data were added together and sub- 
tracted from the total car body air resistance readings, the net 
air resistance data for the car body itself being thus obtained. 

These determinations were then arranged in groups for the 
purpose of averaging the values over certain ranges of speed. 
Naturally these values varied considerably, owing to the fact 
that in the first place, the measurement itself was an extremely 
difficult one to make, and in the second place the effect of wind 
and of the currents of air caused by the different forms of vesti- 
bule introduced variables and indeterminate factors. The 
average data for the groups, therefore, represent approximate 
values of the skin resistance for the average speeds of the groups. 

Results of the Tests. 

The final results of the tests are given in the synopsis and in 
Tables LXXX to LXXXV inclusive. They are also represented 



AIR RESISTANCE TESTS 



553 



in graphical form by the curves shown in Figs. 199 to 204 
inclusive. 

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Fig. 200. — Air Resistance Curves for Parabolic Vestibule. 



60 



measurements, for reasons already stated. The curves were 
plotted to conform to the average direction indicated by the 
location of the selected points. In Tables LXXX to LXXXIII 
inclusive, are shown the results of the air resistance tests with 



554 



ELECTRIC RAILWAY TEST COMMISSION 



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^ 



AIR RESISTANCE TESTS 



555 



the various vestibules. The runs from A to H inclusive, show 
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the suction on the rear vestibule at different speeds. The data 



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showing the air resistance offered by the car body itself have not 
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of curves from the results obtained, but they have been tabu- 
lated and are shown in Table LXXXIV. The power absorbed 
by the various vestibules, when the car is running at a given 
speed, is shown in Table LXXXV, 



556 



ELECTRIC RAILWAY TEST COMMISSION 



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Fig. 203. — Pressure Power Curves for Various Vestibules — Air Resistance Tests. 



AIR RESISTANCE TESTS 



557 



Pigs. 199, 200, 201, and 202 show graphically the vestibule 
data given in Tables LXXX to LXXXIII inclusive. The pres- 
sure on the front vestibule is shown by the upper curve, while 



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Fig. 204. — Suctions — Power Curves for Various Vestibules — Air Resistance Tests 



60 



the lower curve in each case shows the suction on the rear 
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562 



ELECTRIC RAILWAY TEST COMMISSION 



Table LXXXIV. — Car Body Resistance Data. 
Group A — 19 to 30 M.P.H. 



Direction of 
Motion of Car, 



West. . . 

West. . , 

West. . . 

West. . , 

West. . . 

West. . , 

West. . . 

West . . . 

West. . . 

West. . . 

West. . . 

East . . , 

West . . , 
Average 



Speed 
M.P.H. 



19.1 
25.1 

24.8 
24.7 
23.9 
24.1 
26.4 
22.1 
22.6 
28.0 
23.2 
28.4 
19.4 
23.9 



Total Skin 

Resistance 

OF Car Body. 

Lbs. 



154.2 
57.3 
20.2 
14.5 
17.4 
83.4 
21.2 
35.4 
5.0 

163.8 

162.6 
47.6 

107.9 
68.5 



Direction 
OF Wind. 



S.E. 

S. 

W. 

N.W. 

N.W. 

N.W. 

N.W. 

N. 

N.E. 

N.E. 

N.E. 



S.W. 



Velocity of 
Wind M.P.H. 



15.0 

15.0 

21.0 

8.0 

8.0 

7.0 

7.0 

7.0 

5.0 

4.0 

3.0 

7.0 

16.0 



Group B — 30 to 40 M.P.H. 



East 


38.2 


51.2 


S. 


16.0 


West . 










37.8 


87.4 


N.W. 


8.0 


East . 










37.2 


335.7 


N.W. 


8.0 


East . 










36.7 


214.4 


N.W. 


7.0 


West. 










35.2 


135.3 


W. 


6.0 


East . 










39.2 


40.8 


W. 


6.0 


West . 










33.7 


102.8 


N.W. 


22.0 


West. 










32.1 


59.1 


N.W. 


8.0 


East . 










30.1 


42.4 


N.E. 


5.0 


East . 










37.3 


132.9 


N.E. 


5.0 


East . 










31.6 


24.1 


N.E. 


4.0 


West . 










36.4 


181.8 


N.E. 


3.0 


East . 










34.1 


67.8 


S. 


18.0 


Average 






35.4 


113.5 







Group C — 40 to 50 M.P.H. 



East . . . 

East . . . 

West. . . 

East . . . 

West . . , 

East . . . 

East . . . 

West . . . 

West . . , 
Average 



49.0 

47.5 
49.3 
44.0 
47.8 
42.2 
41.1 
45.4 
48.7 
46.1 



34, 

74, 



25.0 



85.1 

52.5 

229.1 

330.9 

72.2 
173.0 
119.6 



S. 

w. 

s. 

N.W. 
S.W. 

N.E. 
N.E. 
N.W. 
W. 



18.0 

21.0 
7.0 

22.0 
9.0 
4.0 
3.0 
6.0 

11.0 



AIR RESISTANCE TESTS 

Table LXXXIY. — Continued. 
Group D — 50 to 60 M.P.H. 



563 







Total Skin 






Direction of 


gPEED 


Resistance 


Direction 


Velocity of 


Motion of Car. 


M.P.H. 


OF Car Body, 

Lbs. 


OF Wind, 


Wind M,P,H, 


West 


52.1 


67.8 


S,W. 


7.0 


East 


57.4 


116.9 


S, 


10.0 


West 


51.8 


88.5 


S, 


11.0 


East 


58.3 


78.2 


s. 


11.0 


West 


50.2 


118.6 


s. 


8.0 


Average . . . 


53.9 


92.0 







Average Speed — 36.4 M.P.H. 
Average Resistance — 97 . 6 Lbs, 



Table LXXXV. — Power Absorbed by Vestibules. 



Type of Vestibule, 



Parabolic Wedge 
Parabola. . . . 
Standard , , . 

Flat 

Parabola. . . . 
Parabolic Wedge 

Flat 

Standard . , . 



Horse-Power Taken by Head 
Pressure and Rear Suction 
at Various Speeds in Miles 
PER Hour. 



20 



2.00 
2.56 
1.69 
7.18 
0.41 
0.97 
0.72 
0.67 



30 


40 


50 


3.69 


7.48 


17.6 


4.84 


9.23 


20.5 


6.92 


20.3 


40.7 


16.9 


36.5 


71.7 


0.69 


1,13 


1.92 


1.54 


2,36 


3.59 


1.31 


2.05 


4.74 


1.69 


4.10 


8.96 



60 



32.2 
36.9 
69.6 
126.0 
3.68 
6.91 
7.68 
16,0 



Remarks. 



Head Pressure 
Head Pressure 
Head Pressure 
Head Pressure 
Rear Suction 
Rear Suction 
Rear Suction 
Rear Suction 



Note, — These data are taken from the curves of Figs. 203 and 204. 



Discussion of Results. 

The curves and tables given in this chapter furnish data for 
showing the pressure exerted on the front of a car and the suction 
on the rear when the car is running at various speeds. Some 
information is also obtained in regard to the side and roof friction. 
While the latter data must be considered as approximate only, 



564 ELECTRIC RAILWAY TEST COMMISSION 

the tests show that the side and roof resistance are small com- 
pared with the head resistance. The determinations of the 
values of the side and roof resistance are made by subtracting 
the combined head and rear resistance from the total air resistance 
of the car at given speeds. As the results show, this difference is 
small and therefore the accuracy of this part of the tests is not 
as great as that of the head and rear resistance, which latter data 
are reasonably close to the actual values, especially those relating 
to the air resistance of the front vestibule. 

THE FRONT VESTIBULE AIR RESISTANCE. 

The head resistances were measured for four different types, 
the parabolic-wedge, the parabola, the flat and the standard 
vestibules respectively. The curves and tables show, as would 
be expected, that the flat form gives by far the highest resistance, 
the standard form being next in order. The standard form of 
vestibule was at a slight disadvantage in comparison with the 
other forms, owing to the fact that it was equipped with side 
doors. While the parabolic wedge and the parabola both had 
a greater longitudinal length than did the standard form, the 
flat vestibule was practically a surface only. Undoubtedly 
this latter vestibule would have shown a considerably increased 
air resistance if it had been provided with side doors such as the 
standard vestibule was equipped with, or if it had been provided 
with extended smooth side surfaces equivalent to those of the 
parabolic wedge and parabola vestibule. 

THE REAR VESTIBULE AIR RESISTANCE. 

In all cases the rear vestibule air resistance proved to be a 
•suction, the effect of which is to retard the motion of the car. 
While the flat form showed the greatest front pressure, an in- 
spection of the data and curves shows that the standard form 
gives the greatest rear suction. This is accounted for by the 
fact that the flat vestibule was a surface only, whereas the 
standard form was equipped with side doors which offered con- 



AIR RESISTANCE TESTS 



565 



siderable resistance to the passage of the car through the air. 
As in the case of the head pressure data, the suction is least for 
the parabola and parabolic wedge forms. 

THE CAR BODY AIR RESISTANCE. 

As previously stated, the car body data was not considered 
to be sufficiently uniform to permit of graphical representation 
in the form of curves. Table LXXXIV shows that the average 



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Fig. 205. — Air Resistance Curves for Parabolic-Wedge Vestibule Extended to 100 M.P.H. 



100 



surface friction of the sides and roof of the car amounts to 
approximately one hundred pounds at an average speed of 36 
miles an hour. This resistance varies over a wide range on ac- 
count of the many indeterminate factors entering into its com- 
position. It is to be expected that the resistance would be 
small at low values of the speed, and that, after rising to a 
maximum at some intermediate speed, it might again decrease 
at the higher speed values, because of the shielding effect of 



566 



ELECTRIC RAILWAY TEST COMMISSION 



the front vestibule upon the sides and roof of the car. It is 
probable that the air is thrown away from the sides at very high 
speeds and this would seem to be indicated by the results given 
in the tables. 

THE EFFECT OF AIR RESISTANCE ON TRAIN RESISTANCE. 

While the effect of the shape of the vestibule upon the train 
resistance is discussed in Chapter XIV, a more specific investiga- 



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Fig. 206. — Air Resistance Curves for Parabolic Vestibule Extended to 100 M.P.H. 

tion, based upon the data of the present chapter, leads to some 
interesting deductions. 

Figures 205, 206, 207, and 208 show the curves of Figures 199, 
200, 201, and 202, extended to a speed of one hundred miles per 
hour. These curves were extended in accordance with the 



AIR RESISTANCE TESTS 



567 



general form of the series, this form being obtained by a detailed 
study of the graphical results of the tests. From these curves 
Table LXXXVI was produced. These data were then used in 



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Fig. 207. —Air Resistance Curves for Flat Vestibule Extended to 100 M.P.H. 



100 



the calculation of the power absorbed by the vestibules expressed 
in horse-power. The latter calculations are shown in Table 
LXXXVII, 



568 



ELECTRIC RAILWAY TEST COMMISSION 



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Fig. 208. — Air Resistance Curves for Standard Vestibule Extended to 100 H/LP.H. 



100 



AIR RESISTANCE TESTS 



569 



Table LXXXVI. — General Results of Air Resistance Tests. (Data Extended 
to Include Speeds up to 150 Miles Per Hour.^) 





Air Resistance in Pounds Per Square Foot at Various 

Speeds. 


Type of Vestibule. 


Miles Per Hour. 




20 


30 


40 


50 


60 


70 80 


90 


100 



PRESSURE. 



Parabolic wedge 

Parabola 

Flat 

Standard 



0.39 


0.48 


0.73 


1.37 


2.10 


2.98 


4.00 


5.20 


0.50 


0.63 


0.90 


1.60 


2.50 


3.48 


4.60 


5.92 


1.40 


2.20 


3.56 


5.60 


8.20 


11.00 


14.00 


17.50 


0.33 


0.90 


1.98 


3.18 


4.53 


6.00 


7.80 


10.25 



6.60 

7.40 

22.00 

13.30 



SUCTION. 



Parabolic wedge 

Parabola 

Flat 

Standard 



0.19 


0.20 


0.23 


0.28 


0.45 


0.67 


0.94 


1.28 


0.08 


0.09 


0.11 


0.15 


0.24 


0.32 


0.42 


0.53 


0.14 


0.17 


0.20 


0.37 


0.50 


0.65 


0.85 


1.15 


0.13 


0.22 


0.40 


0.70 


1.04 


1.43 


1.85 


2.30 



1.62 
0.65 
1.45 
3.78 



Table LXXXVII. — Power Absorbed by Vestibules, Expressed in 

Horse Power? 

PRESSURE. 





PowE« Absorbed in 


Head Pressure and 


Rear Suction H.P. 


Type of Vestibule. 


^iLES Per Hour. 




20 


30 


40 


50 


60 


70 


80 


90 


100 


Parabolic wedge 

Parabola 


2.00 
2.56 

7.18 
1.69 


3.69 

4.84 

16.90 

6.92 


7.48 

9.23 

36.50 

20.30 


17.6 
20.5 
71.7 
40.7 


32.2 

38.9 

126.0 

69.6 


53.4 

62.3 

197.0 

107.5 


82.0 

94.2 

287.0 

160.0 


120.0 
136.3 
403.5 
236.0 


169.0 
189 3 


Flat 


563.0 


Standard 


341.0 







SUCTION. 



Parabolic wedge 

Parabola 

Flat 

Standard 



0.97 


1.54 


2.36 


3.59 


6.91 


12.0 


19.3 


29.5 


0.41 


0.69 


1.13 


1.92 


3.68 


5.74 


8.60 


12.2 


0.72 


1.31 


2.05 


4.74 


7.68 


11.6 


17.4 


26.5 


0.67 


1.69 


4.10 


8.96 


16.0 


25.7 


37.9 


53.0 



41.1 
16.7 
37.1 
96.8 



^ The details of this table, from 20 to 60 miles an hour (inclusive), are shown the 
same as in the Synopsis, Table LXXIII. The data from 70 to 100 miles per hour (inclu- 
sive), have been estimated as described in the text. 

2 The data of this table from 20 to 60 miles per hour (inclusive) are the same as in 
Table LXXXI. The data from 70 to 100 miles per hour (inclusive), have been estimated 
as iu the text. 



570 



ELECTRIC RAILWAY TEST COMMISSION 



If the car were equipped with the same style of vestibule at 
both ends, the data giving the total power in kilowatts, absorbed 
in forcing the two vestibules through the air at various speeds, 
from 20 to 100 miles per hour, would be as shown in Table 
LXXXVIII. In this table the values above 60 miles an hour 
have been obtained by projecting the curves in accordance with 
the same general kw underlying the form of all of the curves of 
the series. 

Table LXXXVIII. — Power Absorbed by Front and Rear Vestibules 

in Kilowatts. 



Type of Vestibule. 


Kilowatts at Various Speeds in Miles Per Hour. 


20 


30 


40 


50 


60 


70 


80 


90 


100 


Parabolic wedge 

Parabola 

Flat 


2.2 
2.2 
5.9 

1.8 


3.9 

4.1 

13.6 

6.4 


7.5 

7.7 

28.7 

18.2 


15.8 
16.7 
57.0 
37.1 


29.2 
30.3 
99.8 
63.9 


48.7 

51.5 

155.7 

99.3 


75.7 

76.7 

202.7 

148.0 


111.7 
110.8 
321.0 
215.5 


157.0 
153.8 
448.0 
327.0 


Standard 





In order to bring out somewhat more perfectly what these 
figures mean. Table LXXXIX has been computed by assuming 
the amount of power required to force a standard front vestibule 
through the air at the variou^ speeds to be 100 per cent, the 
relative amount of power for the other forms of front vesti- 
bule being expressed comparatively. 



Table LXXXIX. — Relative Power Required to Force Front Vestibules Only, 
Through the Air, at Various Speeds. 



Type of Vestibule. 


Per cent at Various Speeds. Miles Per Hour. 




20 


30 


40 


50 


60 


70 


80 


90 


100 


Parabolic wedge 

Parabola 


118.0 
151.0 
100.0 
425.0 


53.5 

70.0 

100.0 

245.0 


36.9 

45.5 

100.0 

180.0 


43.3 

50.5 

100-0 

176.3 


46.3 

53.1 

100.0 

181.2 


49.6 

58.0 

100.0 

183.2 


51.2 

58.8 
100.0 
179.2 


50.8 

57.8 

100.0 

171.0 


49.6 
55 5 


Standard 


100.0 


Flat 


165 







While the experiments are not entirely conclusive, they tend 
to show that a parabolic-wedge front vestibule and a parabolic 

1 Same type of vestibule front and rear, 



AIR RESISTANCE TESTS 



671 



rear vestibule give the best total results and the resistance 
(expressed in kilowatts, at various speeds) offered to the passage 
of this combination of vestibules, as compared with a pair of 
standard vestibules is as shown in Table XC. 



Table XC. — Power Absorbed bij Parabolic-Wedge Front Vestibule and Para- 
bolic Rear Vestibule in Overcoming Air Resistance, as Compared with 
that Absorbed by Standard Front and Rear Vestibules. 



Type of Vestibule. 


Kilowatts at Various Speeds. Miles Per Hour. 


20 


30 


40 


50 


60 


70 


80 


90 


100 


Parobolic wedge front . 

Parabolic rear 

Total, front and rear. . 
Standard interurban, 
front and rear. 


1.5 
0.3 
1.8 
1.8 


2.8 
0.5 
3.3 
6.4 


5.6 

0.8 

6.4 

18.2 


13.1 

1.4 

14.5 

37.1 


23.1 

2.8 

25.9 

63.9 


39.8 

5.0 

44.8 

99.3 


61.2 

6.4 

67.6 

148.0 


89.5 

9.1 

98.6 

215.5 


126.2 

12.5 

138.7 

327.0 



Finally it is important to be able to estimate the total amount 
of power absorbed by a car at various speeds, including the air 
resistance of car body, and also that of the vestibules and 
trucks. 

The data for the air resistance of the car body and vestibule 
are given in Table XCI. In order to obtain these figures it was 
necessary to combine the results of the vestibule and car- 
body resistance tests. The latter tests did not show any law 
of variation between resistance and speed, and in an earlier part 
of this chapter the method used in obtaining the average resis- 
tance was given. In calculating Table XCI this average resis- 
tance was used for all speeds arid the power was calculated by 
multiplying together the resistances and speeds and reducing 
to kilowatts. 

Table XCI. — Power Absorbed by Front and Rear Vestibules and 
Car Body, Kilowatts} 



Type of Vestibule. 


Miles Per Hour. 




20 


30 


40 


50 


60 


70 


80 


90 


100 


Parabolic wedge 

Parabola 

Flat 


5.9 
5.9 
9.6 
5.5 


9.5 

9.7 

19.2 

12.0 


14.8 
15.2 
36.2 
25.7 


25.1 
26.0 
66.3 
46.4 


40.4 

41.5 

111.0 

75.1 


61.8 

64.6 

168.8 

112.4 


90.6 

91.6 

217.6 

162.9 


128.5 
127.6 
337.8 
232.3 


175.6 
172.4 
466.6 


Standard 


345.6 







1 Same type of vestibule front and rear. 



672 



ELECTRIC RAILWAY TEST COMMISSION 



Table XCII. — Total Estimated Power Absorbed in Overcoming Air Resis- 
tance by an Interuban Car Equipped with Various Vestibules} 



Type of Vestibules. 


Total Power Absorbed, Kilowatts. Miles Per Hour, 




20 


30 


40 


50 


60 


70 


80 


90 


100 


Parabolic wedge 

Parabola 


6.6 

6.6 

10.3 

6.2 


11.2 
11.4 
20.9 
13.7 


18.4 
18.8 
39.8 
29.3 


32.2 
33.1 
73.4 
53.5 


5 .9 

54.0 

123.5 

87.6 


81.3 

84.1 

188.3 

131.9 


119.0 
120.0 
246.0 
191.3 


168.5 
167.6 
377.8 
272.3 


231.4 
228.2 
522.4 
401.4 


Flat 


Standard 





In the above table the bottom of the car body is assumed to be three feet above the 
track and the under-body resistance is calculated on the basis of a fiat surface equal to 
one-half of the under-body cross-sectional area, which in this case is 8.5 times 3 or 25.5 
square feet. 

As the arrangement of apparatus beneath the car is dif- 
ferent in the several types of car, only an average value can 
be estimated. It would appear to be a safe assumption to say 
that the resistance below the car would be approximately one- 
half that of a plain surface extending from the car floor to the 
rails. As it is physically impossible to measure this quantity, 
some such assumption as this must be made, and this assumption 
can be checked by comparison with the total car resistance as 
given in Chapter XIV. By making this allowance and combining 
with the data already determined the assumed imder-body 
resistance, the figures given in Table XCII have been obtained. 

It will be noted that the actual experimental data for the flat 
front vestibule did not exceed 50 miles per hour, and the reason 
for this is that it was impossible with the power at hand to force 
the flat-ended car above this speed. This power was sufficient 
to easily permit a speed of 75 miles an hour with the parabolic 
wedge-front vestibule, and this fact gives force to the statements 
already made. Assume for purpose of comparison that of two 
cars one car is equipped with the flat front and one with the 
wedge-shaped front, and that each operates 30,000 car miles per 
year, at an average speed of 50 miles per hour, the annual saving 
in energy of the latter over the former car would be 24,200 kil- 
owatt hours. Nothing more forcibly calls attention to these 

* Same type of vestibule front and rear. 



AIR RESISTANCE TESTS 



573 




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574 ELECTRIC RAILWAY TEST COMMISSION 

facts than to observe the reading of the instruments on the 
djniamometer car when it is equipped with the several forms of 
vestibule. The sensations in this case are somewhat startling. 

In addition to the conclusions based upon the form of the 
vestibule the results also emphasize the importance of reducing 
the number and area of projections from the car surface, as such 
projections act in a manner very similar to the increase of the 
area of a flat front. Hence for high speed cars window casings 
should be kept as nearly flush with the body surface as possible 
and all other unnecessary projections should be eliminated. 

The results of these tests are not only applicable in connection 
with electric cars but they also yield many suggestions regarding 
the construction of steam locomotives and trains. From the 
standpoint of wind resistance nothing worse than the standard 
type of locomotive can be imagined, with its multitude of irreg- 
ular projections. The experience of engineers and firemen in 
putting their heads out of cab windows is such as to demonstrate 
the great resistance met by such obstacles. The resistance 
offered to all high speed steam trains by the air would be mater- 
ially diminished if the locomotive were housed in a shell and if 
pains were taken to remove all unnecessary projections from 
the coaches and, further, if the outline of the tender were made 
to conform to the general cross-sectional shape of the train. 

While something has been accomplished in the present series 
of tests, there is much more to be done, both in the way of work- 
ing up more thoroughly the data already secured and in con- 
tinuing the series of tests. The experience gained with the 
present form of dynamometer car can be utilized so as to render 
further tests much more accurate. It is highly desirable that 
other forms of vestibule be tested and that the resistance of the 
car body proper be more thoroughly investigated. The experi- 
ments should be made with several cars in a train and the effect 
of the wind in all directions should be very carefully studied. 
Fig. 209 shows a sketch of a car modelled in accordance with 
the principles discussed in the present chapter. 



APPENDIX A. 



APPENDIX A. 



GENERAL DATA RELATING TO ELECTRIC CARS. 

Before beginning the experimental work carried on by the 
Electrical Railway Test Commission, its Executive Committee 
found it desirable to make a study of the various types of cars 
employed in the different classes of street and interurban rail- 
way service. Early in the spring of 1904, a preliminary blank 
form was sent to a number of manufacturers of car bodies, 
trucks, and electrical equipment, in order to ascertain the usual 
practice in regard to the weights of these component parts of 
an electric car and the number and capacity of the motors used 
in the various kinds of service. This blank form is shown 
in Fig. 210. 



Universal Exposition, St. Louis, 1904, Electric 
Railway Test Coi^oiission. 

Electric Railway Equipment for Various Classes of Service. 





Equipments for 




Light Ci 

Service 


TY 


Heavy City 
Service. 


Light Interur- 
ban Service. 


Heavy 

URBAN 


Inter- 
Service. 


Range of car body 

weights. 
Range of truck 

weights (total). 
Range of total 

weights of 

equipped cars. 
Usual number of 


From .... 

to 

From .... 

to 

From .... 
to 


. lbs. 
. lbs. 
. lbs. 
. lbs. 
. lbs. 
. lbs. 


From lbs. 

to lbs- 

From lbs. 

to lbs 

From lbs. 

to lbs. 


From lbs. 

to lbs. 

From lbs. 

to lbs. 

From lbs. 

to lbs. 


From 
to . .. 
From 
to . .. 
From 
to . . . 


.... lbs. 
.... lbs. 
.... lbs. 
.... lbs. 
.... lbs. 
.... lbs. 


motors 
Range of total h.p. 

of motors. 
Remarks 


From .... 
to 


h.p. 
h.p. 


From .... h.p. 
to h.p. 


From .... h.p. 
to h.p. 


From 
to . .. 


... h.p. 
... h.p 













Fig. 210. — Information blank used in obtaining preliminary data as to usual practice 
in the construction of electric cars. 

677 



m 



ELECTRIC RAILWAY TEST COMMISSION 



Table XCIII. 



— Classification of Electric Cars. 
Light City Service 



Range of Car Body 
Weiglits in Lbs. . . 

Range of Truck 
Weiglits (Total) in 
Lbs 

Range of Total 
Weights of Equipped 
Cars in Lbs 

Usual Number of 
Motors 



Range of Total H.P. 
of Motors 



Company 



mm. 

max. 

ave. 

min. 

max. 

ave. 

min. 

max. 

ave. 

min. 

max. 

ave. 

min. 

max. 

ave. 



A* 



8 000 
12 000 
10 COO 

4 700 

9 000 
6 850 

17 700 

31 000 

24 350 

1 

4 

2 

25 

50 

37.5 



B 



8 000 
10 000 
10 000 

5 000 
7 500 

6 250 
16 300 
21 100 
18 700 

2 

* v 

35 
80 
57.5 



C 



500 
000 
250 
500 
000 
750 



Z> 



10 700 
12 500 

11 600 

17 300 
19 500 

18 400 
28 000 
32 000 
30 000 

2 

' '2* 
60 
80 
70 



E 



7 000 

8 000 
6 500 

4 500 

5 000 
4 750 

15 000 

16 000 
15 500 

2 

' '2' 

50 

80 
65 



5 000 

10 000 

7 500 

4 000 

5 000 
4 500 

18 OOOt 

30 OOOt 

24 OOOt 

2 

' '2' 
50 
80 
65 



Ave. 



7 530 
10 080 

8 810 

6 670 
8 500 

7 580 
19 000 
26 020 
22 510 

2 

4 

2 
45 
75 
60 



Heavy City Service 



Range of Car Body 
Weights in Lbs. . . 

Range of Truck 
Weights (Total) in 
Lbs 

Range of Total 
Weights of Equipped 
Cars in Lbs 

Usual Number of 
Motors 



Range of Total H.P. 
of Motors 



min. 


t 
12 000 


16 000 


12 000 


14 500 


12 000 


13 000 


max. 


20 000 


23 000 


16 000 


16 000 


12 000 


18 000 


ave. 


16 000 


19 500 


14 000 


15 250 


12 000 


15 500 


mm. 


9 000 


10 000 


7 000 


19 500 


8 000 


10 000 


max. 


16 000 


12 000 


12 000 


20 900 


8 000 


15 000 


ave. 


12 500 


11 000 


9 500 


20 200 


8 000 


12 500 


mm. 


35 000 


32 000 


, , . 


34 000 


30 000 


35 OOOt 


max. 


50 000 


45 000 


. • • 


36 900 


30 000 


50 OOOt 


ave. 


42 500 


38 500 


, . 


35 450 


30 000 


42 500t 


mm. 


4 


4 


2 


4 


4 


2 


max. 


• . . 


, . 


4 


• • . 


• . • 


4 


ave. 


4 


4 


4 


4 


4 


4 


mm. 


35 


100 


100 


• • • 


140 


100 


max. 


60 


160 


140 


• • • 


140 


150 


ave. 


47.5 


130 


120 


. . . 


140 


125 



13 250 

17 500 

15 380 

10 580 

13 980 

12 280 

33 200 

42 380 

37 790 

4 

4 

4 

95 

130 

115 



Light Interurban Service 



Range of Car Body 
Weights in Lbs. 

Range of Truck 
Weights (Total) in 
Lbs 

Range of Total 
Weights of Equipped 
Cars in Lbs 

Usual Number of 
Motors 

Range of Total H.P. 
of Motors 



( min. 


§ 
16 000 


20 000 


16 000 


16 800 


16 000 


14 000 


< max. 


25 000 


24 000 


22 000 


20 000 


16 000 


20 000 


( ave. 


20 500 


22 000 


19 000 


18 400 


16 000 


17 000 


( min. 


10 000 


11 000 


10 000 


22 000 


10 000 


10 000 


< max. 


18 000 


13 000 


12 500 


23 500 


10 000 


15 000 


( ave. 


14 000 


12 000 


11 250 


22 750 


10 000 


12 500 


( min. 


35 000 


42 000 


• • • 


38 800 


42 000 


40 OOOt 


I max. 


55 000 


48 000 


• • • 


43 500 


42 000 


60 OOOt 


[ ave. 


45 000 


45 000 


, , 


41 150 


42 000 


50 OOOt 


( min. 


4 


4 


4 


4 


4 


2 


< max. 


• . . 


• • • 


. . . 


• • • 


• • • 


4 


' ave. 


4 


4 


4 


4 


4 


4 


( min. 


40 


160 


• • • 


200 


200 


150 


< max. 


70 


200 


• • • 


250 


200 


200 


ave. 


55 


180 


. . • 


225 


200 


175 



16 470 
21 170 
18 820 

12 170 
15 330 

13 750 
39 560 
49 700 
44 630 

4 

4 

4 
150 
185 
170 



Heavy Interurban Service 



Range of Car Body 
Weights in Lbs. . . 

Range of Truck 
Weights (Total) in 
Lbs 

Range of Total 
Weights of Equipped 
Cars in Lbs 

Usual Number of 
Motors 

Range of Total H.P. 
Motors 



min. 


II 
25 000 


25 000 


25 000 


35 000 


30 000 


25 000 


max. 


36 000 


40 000 


35 000 


45 000 


30 000 


40 000 


ave. 


30 500 


32 500 


30 000 


40 000 


30 000 


32 500 


mm. 


20 000 


14 000 


18 000 


25 000 


13 000 


16 000 


max. 


36 000 


16 000 


25 000 


40 000 


13 000 


22 000 


ave. 


28 000 


15 000 


21 500 


32 500 


13 000 


19 000 


mm. 


50 000 


50 000 


, , , 


60 000 


67 000 


65 OOOt 


max. 


80 000 


75 000 


• . • 


85 000 


67 000 


85 OOOt 


ave. 


65 000 


62 500 


• . • 


72 500 


67 000 


75 OOOt 


mm. 


4 


4 


4 


4 


4 


2 


max. 






, , . 


• . . 


• . . 


4 


ave. 


4 


4 


4 


4 


4 


4 


mm. 


60 


200 


• . • 


240 


500 


300 


max. 


200 


700 


, ^ 


320 


500 


500 


ave. 


130 


450 




280 


500 


400 



27 500 

37 670 

32 580 

17 670 

25 330 

21 500 

58 400 

78 400 

63 200 

4 

4 

4 

250 

450 

350 



* Calculated on use of single and maximum traction truck. 

t With seated load. § Are usually equipped with power brakes. 

$ With and without vestibule. || Speed up to 80 miles per hour. 



APPENDIX A 579 

In conducting this investigation, it was necessary to make a 
general classification of electric cars which was done by dividing 
the equipment into the following groups : 

A. Light city service. 

B. Heavy city service. 

C. Light interurban service. 

D. Heavy interurban service. 

As the result of this preliminary canvass, a number of useful 
data were obtained which are shown in Table XCIII. 

After the preliminary study, a second and more complete 
blank form was prepared, and sent out during the summer of 
1904, to a large number of manufacturing and operating com- 
panies for the purpose of securing further and more detailed 
data and general information concerning the electric cars used 
in the United States. This form is shown in Fig. 211. 

The responses to this request for information were quite 
general and many of the companies furnished much valuable 
data. Some of the principal cooperating companies were the 
following: 

1. Aurora, Elgin & Chicago Railway Company, Chicago, HI. 

2. Berkshire Street Railway Company, Pittsfield, Mass. 

3. Birmingham Railway Light & Power Company, Birmingham, Ala. 

4. Boston Elevated Railway Company, Boston, Mass. 

5. Brooklyn Heights Railroad Company, Brooklyn, N. Y. 

6. Capital Traction Company, Washington, D. C. 

7. Chicago City Railway Company, Chicago, 111. 

8. Cleveland Electric Railway Company, Cleveland, O. 

9. Columbus, Buckeye Lake & Newark Traction Company, Columbus, O, 

10. Columbus, Newark & Zanesville Electric Railway Company, Columbus, O. 

11. Detroit United Railway, Detroit, Mich. 

12. Indianapolis and Northwestern Traction Company, Indianapolis, Ind. 

13. Interborough Rapid Transit Company, New York City. 

14. Louisville Railway Company, Louisville, Ky. 

15. Marquette City & Presque Isle Railway Company, Marquette, Mich. 

16. Metropolitan Street Railway Company, Kansas City, Mo. 

17. New Orleans Railways Company, New Orleans, La. 

18. New York City Railway Company, New York City. 

19. Norfolk Railway & Light Company, Norfolk, Va. 

20. Northwestern Elevated Railroad Company, Chicago, 111. 



ELECTRIC RAILWAY TEST COMMISSION. 



DATA SHEE ". 

Number Date . 

Source of Information 





CAR BODY. 

DATA. 


REMARKS. 


Make 






Type 






Length — over corner posts 






Length — over corner posts 






Length — front platform 






Length — rear platform 






Width — over all 






Weight 






Weight — equipped 






Number of seats 






Kind of seats 






Capacity — seating 






Capacity — standing * 






Shape of front 







* Allowing square feet per passenger. 

TRUCKS. 



Make 






Type 






Weight 






Carrying capacity 






Speed rating 






Wheel base 






Distance between truck centers 






Diameter of wheels 






Diameter of axles 






Size of journals 






System of springs 






Kind of tires 







4 



MOTORS. 



Make 






Type 






Number per car 






Voltage 






Capacity (one hour rating) 






Gear ratio 






Weight (total) 






Weight (armature) 






Diameter of armature 






Size of bearings 






Arrangement on trucks 






Method of suspension 






Maximum speed 









GENERAL EQUIPMENT. 




Hand brake 






Power brake 






System of control 






Type of controller 






Method of heating 






Trolley stand 






Trolley wheel 






Circuit breakers 






Number of lamps 






Kind and position of headlight 







Height of car floor from track 



Height of car roof from track 



Weight of car complete 



Fig. 211,'— Information Blank Used in Obtaining Gensra' Dx'a Consrnrnj Electric Cars 



APPENDIX A 581 

21. Philadelphia Rapid Transit Company, Philadelphia, Pa. 

22. Pittsburg Railways Company, Pittsburg, Pa. 

23. Public Service Corporation of New Jersey, Jersey City and Newark, N. J. 

24. The Rhode Island Company, Providence, R. I. 

25. Schenectady Railway Company, Schenectady, N. Y. 

26. St. Louis Transit Company, St. Louis, Mo. 

27. Tri-City Railway Company, Davenport, la. 

28. Twin City Rapid Transit Company, Minneapolis, Minn. 

29. United Railroads of San Francisco, San Francisco, Cal. 

30. United Railways & Electric Company of Baltimore, Baltimore, Md. 

31. Virginia Passenger & Power Company Richmond, Va. 

32. Worcester Consolidated Street Railway Company, Worcester, Mass. 

After this information had been carefully studied and tabu- 
lated, it was found that the data were defective in certain 
particulars. During the winter and spring of 1904-1905, a 
second attempt was made to fill in the missing items, and after 
this second canvass had been completed, there were sufficient 
data at hand to enable the committee to tabulate a number 
of data relating to the present American practice in the use of 
electric cars for street and interurban purposes. 

The Tabulated Results. 

Tables XCVIV to XCVIII, inclusive, show the results of this 
investigation as they were obtained from the principal cooperat- 
ing companies previously mentioned. Table XCIV refers to 
light city service, Tables XCV and XCVI show the data ob- 
tained for heavy city service conditions. Table XCVII gives 
the results for light interurban conditions, while Table XCVIII 
the data relating to heavy interurban service. 



582 



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ELECTRIC RAILWAY TEST COMMISSION 



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APPENDIX A 587 

Tables of Average Data. 

While the general data are given in each instance in Tables 
XCIV to XCVIII inclusive, it has been considered advisable to 
place the average values by themselves in separate tables, 
so that they may be more conveniently compared. These 
data are contained in Tables XCIX to CII inclusive. 

Table XCIX. — Average Data for Light City Service. 

Car Body. 

Length over bumpers 29 feet, 6 inches. 

Length over comer posts 21 feet, mches. 

Length of platforms 3 feet, 11 inches. 

Width over all 7 feet, 11 inches. 

Weight 7,570 lbs. 

Weight equipped 8,400 lbs. 

Capacity seating 33 

Capacity standing 32 

Trucks. 

Weight 5,090 lbs. 

Carrying capacity 23,200 lbs. 

Speed rating 18 5 m.p.h. 

Wheel base 6 feet, 6 inches. 

Diameter of wheels 33 inches. 

Diameter of axles 4 inches. 

Size of journals 3^ inches X 7f inches. 

Motors. 

Number per car 2 

Voltage 550 

Capacity (one hour rating) 37 h.p. per motor 

Gear ratio 4 . 455 

Weight total • 2,194 lbs. per motor. 

Weight of armature 549 lbs. 

Diameter of armature 14 inches. 

Size of bearings C. E. 2f inches X 6i inches. 

P. E. 3 inches X 7f inches. 

General Data, 

Height of car floor from trade 34 inches. 

Height of car roof from track 11 feet, mches. 

Weight of car complete 18,800 lbs. 



588 ELECTRIC RAILWAY TEST COMMISSION 

Table C. — Average Data for Heavy City Service. 

Car Body. 

Length over bumpers 40 feet. 9f inches. 

Length over comer posts 31 feet, 7^ inches. 

Length of platforms 4 feet, 6| inches. 

Width over all 8 feet, 4^ inches. 

Weight 16,600 lbs. 

Weight equipped 18,730 lbs. 

Capacity seating 46 

Capacity standing 50 

Trucks. 

Weight 5,790 lbs. 

Carrying capacity ". 25,400 lbs. 

Speed rating 26 m.p.h. 

Distance between truck centers 19 feet, 2 inches. 

Wheel base 4 feet, 8 inches. 

Diameter of wheels 33 inches. 

Diameter of axles 4| inches. 

Size of journals 3^ inches X 7f inches. 

Motors. 

Number per car 2 or 4. 

Voltage 500 and 550. 

Capacity (one hour rating) 43 h.p. and 35 h.p. 

Gear ratio 4.15 and 4.26. 

Weight (total) 2,760 lbs. and 2,376 lbs. 

Weight (armature) 704 lbs. and 552 lbs. 

Diameter of armature 14^ inches and 14 inches. 

Size of bearings C.E. 2| inches X 6f inches. 

P.E. 3^ inches X 8| inches. 

General Data. 

Height of car floor from track 38^ inches. 

Height of car roof from track . 11 feet, 9^ inches. 

Weight of car complete 37,100 lbs. 

Table CI. — Average Data for Light Interurban Service. 

Car Body. 

Length over bumpers 41 feet, 2 inches. 

Length over corner posts 31 feet, 2| inches. 

Length of platforms 4 feet, lOf inches. 

Width over all 8 feet, 6 inches. 

Weight 16,410 lbs. 

Weight equipped 19,230 lbs. 

Capacity seating 51. 

Capacity standing. 36. 



APPENDIX A 589 

Table CI. — Continued. 

Weight ' ■ 4,870 lbs. 

Carrying capacity 25,100 lbs. 

Speed rating 31 m.p.h. 

Wheel base 4 feet, 6 inches. 

Distance between truck centers 19 feet, 9 inches. 

Diameter of wheels 33 inches. 

Diameter of axles 4 inches. 

Size of journals 3f inches x 6^ inches. 

Motors. 
Number per car 2 or 4. 

Voltage 550. 

Capacity (one hour rating) 42 h.p. and 45 h.p. 

Gearratio 3 . 98 and 2 . 877. 

Weight total 2,510 lbs. and 2,740 lbs. each. 

Weight (armature) 592 lb. and 666 lbs. 

Diameter of armature 14 inches. 

Size of bearings C. E. 2f inches x 6^ inches. 

P. E. 3^ inches X 8^ inches. 
General Data. 

Height of car floor from track 38^ inches. 

Height of car roof from track 11 feet, 8^ inches. 

Weight of car complete 37,100 lbs. 

Table CII. — Average Data for Heavy Interurhan Service. 

Car Body. 

Length over bumpers 50 feet, 4^ inches. 

Length over comer posts 40 feet, 3| inches. 

Length of platforms 4 feet, 8| inches. 

Width over aU . . 8 feet, 8 inches. 

Weight 27,450 lbs. 

Weight equipped 31,350 ]^s. 

Number of seats 27 

Capacity seating 54 

Capacity standing 57 

Trucks. 

Weight 8,540 lbs. 

Carrying capacity 36,400 lbs. 

Speed rating 54 m.p.h. 

Distance between truck centres 29 feet, 3 inches. 

Wheel base 6 feet, 2^ inches. 

Diameter of wheels 34 inches. 

Diameter of axles 5^ inches. 

Size of journals 4| inches X 8 inches. 



590 ELECTRIC RAILWAY TEST COMMISSION 

Table CII. — Continued. 

Motors. 

Number per car 4. 

Voltage 550. 

Capacity (one hour rating) . 70 h.p. 

Gearratio 2.395. 

Weight (total) 3,660 lbs. 

Weight (armature) 1,000 lbs. 

Diameter of armature 16 inches. 

Size of bearings C. E. 3^ inches x 7| inches. 

P. E.,3f inches X 9 inches. 

General Data. 

Height of car floor from track 45f inches. 

Height of car roof from track 12 feet, 7^ inches. 

Weight of car complete . 62,800 lbs. 



I APPENDIX B. 



f 



APPENDIX B. 



ACKNOWLEDGMENTS. 

It is most fitting, in bringing this Report to a close, to make 
acknowledgment of the valuable assistance that has been 
afforded the Commission, not only in a financial way, but also 
in hearty cooperation by manufacturers and institutions in 
the loan of equipment and apparatus, and by individuals in the 
devotion of much valuable time and thought to the work. 

Financial Assistance. 

While the work of the Commission was done under the aus- 
pices of the Louisiana Purchase Exposition, no direct cash 
appropriations were made by the Exposition for carrying out 
the investigations. Although it was not necessary to make 
expenditures either for equipments to test, or for instruments 
used in these tests, there were many items of expense connected 
with a series of tests extending over a period of nine months, 
followed by a second period of time of equal duration necessary 
to the working up of the data and the production of the final 
Report. Chief among these expense items were the cost of the 
transportation and maintenance of the Testing Corps and allow- 
ances to the Superintendents, the expenditures incident to the 
construction of the car "Louisiana" and those involved in 
putting the data in final form. 

One of the first duties of the Commission was that of raising 

sufficient funds to carry on the w^ork. This was accompUshed 

by subscriptions obtained from various electric railway and 

manufacturing companies, and from the individual members 

of the Commission. Between nine and ten thousand dollars 

693 



594 ELECTRIC RAILWAY TEST COMMISSION 

were contributed from various sources, and a statement of the 
contributors and the amounts contributed will be found in 
the Treasurer's Report. 

REPORT OF THE TREASURER. 
Receipts. 

Individual subscriptions of Commissioners. (See ex- 
hibit "A" for detail) $2,250.00 

Subscriptions of railway companies, bankers, engineer- 
ing firms and companies, etc., less exchange on out 
of town checks. (See exhibit ''B" for detail) . . . 7,529.02 

Cash contribution by Superintendents. (See exhibit 

''C" for detail) 73.93 

Total net cash receipts $9,852 . 95 

Disbursements. 

Stationery, printing, and postage expenses at New 

York City $ 54.35 

Miscellaneous expenses^ at 

St. Louis, Mo 4,623.75 

Anderson, Ind 3,639 . 52 

Ithaca, N.Y 1,535.33 

Total Disbursements $9,852.95 

(Signed) H. H. Vreeland, Treasurer. 

Exhibit "A." 

Individual Subscriptions of Commission. 





Original 
'ubscription 


Additional 
Subscription 


Total 


J. G. White 

James H. McGraw 

W. J. Wilgus 

G. F. McCullough 

H. H. Vreeland 


$200.00 
200 . 00 
200 . 00 
200 . 00 
200 . 00 


$500 . 002 
250 . 002 

' 250.00 ' 
250.00 


$700.00 
450.00 
200.00 
450 . 00 
450.00 


Total 






$2,250.00 



^ See exhibit ''D " for details. 

2 Mr. White's check for $500.00 and Mr. McGraw's check for $250.00, were 
sent direct to the Executive Committee without passing through the treasurer's 
hands. 



Appendix b 



595 



i 



Exhibit "B.'' 

Subscriptions of Railway Companies, Bankers, Engineering Firms and 

Companies, etc. 

American Railways Co., Philadelphia, Pa., for — 
Chicago & Joliet Elect. Ry. Co., 
Springfield, O., Ry. Co., 
The Peoples Ry. Co., Dayton, O., 
Altoona & Logan Valley Elec. Ry,, 

Bridgeton, N. J. & Millville Trac. Co $50.00 

Boston & Northern R. R. Co 50.00 

Old Colony Street Ry. Co 50.00 

Augusta, Ga., Ry. & Elect. Co 50.00 

Butte, Mont., El. Ry. Co 25.00 

Louisville, Ky., Ry. Co 100.00 

Brooklyn Rapid Transit Co 250.00 

Philadelphia Rapid Transit Co 250.00 

Twin City Rapid Transit Co 150.00 

Schnectady Ry. Co 50.00 

The Beaver Valley Traction Co 25.00 

Southern Light & Traction Co 25.00 

Chicago & Milwaukee Elec. Ry. Co 25.00 

Scranton Ry. Co 50.00 

New York City Ry. Co 250.00 

Providence & Danielson Ry. Co 10.00 

The Northern Ohio Traction & Light Co 50.00 

Duluth St. Ry. Co 50.00 

Montreal St. Ry. Co 150.00 

Urbana & Champaign G. & E. Co 25.00 

United Railroads of San Francisco 100.00 

Stone & Webster 350.00 

Contributed for The Seattle Electric Co., Columbus Railway Co., 
El Paso Electric Railway Co., Jacksonville Electric Co., The 
Houghton County St. Ry. Co., Whatcom County Ry. & Lt. Co., 
Savannah Electric Co., Dallas Electric Corporation, Tampa Elec- 
tric Co., Terre Haute Electric Traction Cos., Houston Electric Co. 

Indiana Railway Co 25.00 

British Columbia Electric Ry. Co. . 25.00 

St. Louis & Suburban Ry. Co 50.00 

East St. Louis & Suburban Ry. Co 50.00 

Indiana Union Traction Co 50.00 

Capital Traction Co 50.00 

Toronto Ry. Co 150.00 

Central Pennsylvania Traction Co 50 . 00 

Wheeling & Elm Grove R. R. Co 25.00 

Public Service Corporation of N. J 250.00 

New Orleans Railways Co 100.00 

Indianapolis & N. W. Traction Co 50.00 



596 



ELECTRIC RAILWAY TEST COMMISSION 



Exhibit "B'^ (continued). 

Conn. Ry. & Lighting Co SlOO.OO 

Ft. Wayne & Wabash Valley Trac. Co 25.00 

California Gas & Electric Corporation 25 . 00 

Interborough R. T. Co 250 00 

The Mexico Electric Tramways Co. Ltd 50.00 

Manila Electric R. R. Co. & Lighting Corporation 25.00 

Birmingham Ry. Lighting & Power Co 25 . 00 

The United Railways & Electric Co. of Baltimore 150.00 

Louisville & S, Ind. Trac. Co 25.00 

Lack. & Wyoming Valley R. R. Co 25.00 

Tucker Anthony & Co., Boston 100.00 

Rochester Ry, Co 50 . 00 

The Rhode Island Company , 150.00 

International Ry. Co., Buffalo 150.00 

Detroit United Ry. Co 150.00 

Rapid Ry. System, Detroit 100.00 

St. Louis Transit Co 200 . 00 

Pennsylvania, N. Y. & L. I. R. R. Co 100.00 

Ford, Bacon & Davis 200.00 

Boston Elevated Ry. Co 250.00 

Washington Ry. & Electric Co. ; 100.00 

Richmond Lt. & R. R. Co., Staten Island 75.00 

Boston & Worcester Street Ry. Co 200.00 

Met. St. Ry. Co., Kansas City, Mo 25.00 

Westinghouse, Church, Kerr & Co. 200.00 

North Shore R. R. Co. (John Martin), San Francisco 25.00 

New York Central & Hudson River R. R. Co 300.00 

Binghamton Ry. Co 50.00 

Nashville Ry. & Light Co 50.00 

Milwaukee Elec. Ry. & Light Co 200.00 

Chicago City Ry. Co 250.00 

City & Suburban Ry. Co., Portland, Ore 50.00 

Sanderson & Porter 50.00 

Pittsburgh Railways Co 250.00 

Cleveland Electric Ry. Co. 150.00 

W. E.Baker & Co 100.00 

Portland R. R. Co., Portland, Me 50.00 

New York & Queens Co., Ry. Co 50.00 

Elmira Water, Light & R. R. Co 50.00 

Arnold Electric Power Station Co 50 . 00 

Bion J. Arnold 50.00 

The Ottawa Electric Ry. Co 50.00 

Total $7,535.00 

Less exchange on out of town checks 5 . 98 

Total $7,529.02 



APPENDIX B 
Exhibit "C' 

Contribution by Superintendents} 
Joint Contribution of H. H. Norris and B. V. Swenson . 



597 



$73.93 



Exhibit "D.'^ 

Table Showing Distribution of Expenses. Electric Railway Test Commission 

Executive Committee. 



Items. 


At 

St. Louis. 


At 
Anderson. 


At 
Ithaca. 


Totals. 


Transportation Test Corps 
Transportation Supts. . . 
Support Test Corps . . . 
Allowance to Supts. . . . 
Office Expenses .... 
Construction of apparatus 
Freight and express . . . 
Repairs to apparatus , . 




$555.60 

270.64 

2,061.87 

1,453.85 

42.45 

118.54 

119.30 

1.50 


$39.28 

16.60 

869 . 65 

1,190.00 

124.31 

1,237.63 

156.10 

5.95 


$2.30 

91.12 

5.62 

775.50 

515.70 

113.38 

22.71 

9.00 


$597.18 
378.36 

2,937.14 

3,419.35 
682.46 

1,469.55 

298.11 

16.45 


Totals 




$4,623.75 


$3,639.52 


$1,535.33 


$9,798.60 



Principal Cooperators. 

During the progress of the investigation, many manufacturing 
companies, firms, institutions, and individuals assisted in the 
work of the Commission in one way or another. While it 
would be quite out of the question to make specific acknowledg- 
ments in all such instances, it is the pleasure of the Commission 
to mention some of the principal ones. These have been ar- 
ranged in alphabetical order and acknowledgments to indi- 
viduals have, in general, been made under the name of the 
company, firm, or institution with which the person was iden- 
tified. 

* This subscription was supplied direct to the Executive Committee, 
without passing through the treasurer's hands. In addition to this cash 
contribution, Messrs. Norris and Swenson devoted much of their time to 
the production of the Report from July 15, 1905, to February 1, 1906, without 
compensation. 



598 ELECTRIC RAILWAY TEST COMMISSION 

AMERICAN GAGE COMPANY. 

The American Gage Company supplied special pressure gages 
for use in several of the tests. This company had an extensive 
exhibit of their various gages and appliances in the Palace of 
Machinery at the St. Louis Exposition. The members of the 
Executive Committee and the Test Corps were shown great 
courtesy by those in charge of the exhibit. 

AMERICAN STEEL AND WIRE COMPANY. 

This company, through its district manager, Mr. 0. B. Bar- 
rows, contributed in no small degree to the success of the tests 
upon the groimds of the Exposition. It furnished the trolley 
wire for the test tracks and placed the services of one of its sup- 
erintendents at the disposal of the Commission to supervise the 
erection of the line and to oversee the installation of the rail 
bonds, which were also furnished by the company. The Ameri- 
can Steel and Wire Company supplied several thousand feet 
of No. 0. B. & S. gage duplex lead covered cable for use in 
connecting the exhibit of the Bullock Electric Manufacturing 
Company with the test tracks. This cable was in continual 
use during the investigations of the effects of alternating current 
in a constructed track, the results of which tests comprise the 
material contained in Chapter XIII. 

THE AMERICAN STREET AND INTERURBAN RAILWAY 

ASSOCIATION. 

The American Street and Interurban Railway Association 
rendered important service to the Commission by permitting 
Prof. Bernard V. Swenson, Secretary of the Association, to 
devote a considerable portion of his time for several months 
after his election to the work of the preparation of the Report. 
This service was especially appreciated by the Commission from 
the fact that the duties required of Professor Swenson by the 
Association were most urgent. However, through the cour- 



APPENDIX B 599 

tesy of President Ely and the other members of the Executive 
Committee, matters were so adjusted that Professor Swenson 
was enabled to devote a large amount of energy and time to 
this work. 

BALDWIN LOCOMOTIVE WORKS. 

While the Baldwin trucks used under the ''Louisiana" were 
loaned to the Commission by the Indiana Union Traction Com- 
pany, the Baldwin Locomotive Works made certain changes 
in these trucks which were necessary to adapt them to the 
special conditions which existed in these tests. These changes 
included the designing and construction of special center and 
side bearings, all of which work was done without expense to 
the Commission. These changes in construction are illustrated 
in Chapter XV. 

J. G. BRILL COMPANY. 

The J. G. Brill Company rendered most important aid to the 
Commission by placing at its disposal a special interurban car 
body for use in the air resistance tests. This car body is the 
one used in the construction of the "Louisiana" and is fully 
described in Chapter XV. In adcUtion to supplying the car 
body, this Company further contributed a specially designed 
paraboHc steel vestibule to be used in connection with the air 
resistance measurements. It also supplied a standard vesti- 
bule of the type ordinarily fitted to an interurban car body 
such as the one contributed. 

The Commission also wishes to acknowledge the many valu- 
able suggestions relating to the air resistance tests given by 
Mr. Samuel Curwen, General Manager, and by Mr. W. H. Hue- 
lings, Jr., Secretary of the Company. 

BULLOCK ELECTRIC MANUFACTURING COMPANY. 

This company placed at the disposal of the Commission the 
larger part of its exhibit in the Palace of Electricity at the 
St. Loui^ Exposition^ for use in connection with the tests of 



600 ELECTRIC RAILWAY TEST COMMISSION 

alternating current losses in rails and in track, which tests are 
fully described in Chapters XII and XIII. This exhibit was 
admirably adapted for the purpose and comprised a number of 
machines of large size and of various types which, through the 
courtesy of the company, were operated under the most severe 
conditions in order that the series of measurements made might 
be both complete and comprehensive. The officials of the com- 
pany and their local representative, Mr. Dunfield, aided the 
Comimission in this series of tests in every possible way. Mr. 
Ward S. Arnold, of this company, was a member of the 
Advisory Committee. 

CHAPMAN DOUBLE-BALL BEARING COMPANY. 

This company provided a set of eight large double-ball bear- 
ings for the support of the car body of the ^' Louisiana." It also 
prepared twelve special small bearings for use in connection 
with the vestibule guide frame of the same car. Through its 
local representative, Mr. E. C. Fisher, and its President, Mr. 
Herbert E. Diclison, the company was at all times ready to 
assist the Commission. 

CINCINNATI CAR COMPANY. 

The Cincinnati Car Company placed at the disposal of the 
Commission a modern double-truck city car which it had con- 
structed for the Indiana Union Traction Company. This car 
was a joint exhibit at the Exposition of the Cincinnati Car 
Company and the Westinghouse Companies. It was tested 
under various conditions of operation on the lines of the Indiana 
Union Traction Company. These tests are fully considered in 
Chapters IV, VI, and IX, while the car is fully described and 
illustrated in Chapter I. 

The Commission also wishes to acknowledge the personal 
courtesies and assistance tendered by the President of the 
company, Mr. W. Kelsey Schoepf, who was not only instru- 
mental in placing the interurban car at the disposal of the 



APPENDIX B 601 

Commission, but who also, in his capacity of director of the 
Indiana Union Traction Company, extended to the Commission 
the use of that company's system in the tests which were made 
on Car No. 284 and also those made on the '' Louisiana." 

CORNELL UNIVERSITY. 

Cornell University, through the head of the electrical depart- 
ment. Professor Harris J. Ryan, and the assistant professor 
of electrical engineering, Professor H. H. Norris, placed at the 
disposal of the Commission such apparatus as could be spared 
from the University Equipment, including a considerable 
number of electrical instrimients. The University authorities 
also contributed in no small degree to the work of the Com- 
mission by granting a leave of absence to Professor Norris to 
take up the work of the Commission at St. Louis and, after his 
return to the University, by allowing him to devote a large 
portion of his time to the preparation of the Report of the 
Commission. The increased responsibilities of Professor Norris, 
due to his promotion to the position of professor in charge of 
the electrical engineering department, caused a very con- 
siderable sacrifice on the part of the University during the 
closing months of the year 1905. 

CROSBY STEAM GAGE COMPANY. 

The Crosby Steam Gage Company, which had a most compre- 
hensive exhibit of gages and auxiliary appliances in the Palace 
of Machinery at the St. Louis Exposition, placed at the disposal 
of the Commission its facilities for calibrating pressure gages. 
Those in charge of this exhibit extended most courteous assis- 
tance to the Executive Committee and the members of the 
Test Corps in this work. 

DAYTON ELECTRICAL MANUFACTURING COMPANY. 

The Dayton Electrical Manufacturing Company supphed, for 
the purpose of making speed measurements, two of its small 



602 ELECTRIC RAILWAY TEST COMMISSION 

"Apple" generators, ordinarily used for ignition purposes in 
connection with gas engines, particularly those used for auto- 
mobiles and motor boats. These generators were found to 
serve their purpose most admirably. 

THE ELECTRIC RAILWAY AND EQUIPMENT COMPANY. 

This company through the Wesco Company, supplied the 
tubular iron poles of its manufacture for the equipment of the 
testing tracks and also the brackets for supporting the trolley 
wires. These brackets were specially constructed for the pur- 
pose and were made ornamental to conform with the exhibit 
character 6f the installation. 

ELECTRIC STORAGE BATTERY COMPANY. 

This company, through its Chicago office, furnished portable 
storage batteries for supplying the current for the speed gen- 
erator, the General Electric recording gnnmeter, and the sig- 
nalling devices, furnishing whatever batteries were requested 
for this purpose without expense to the Commission. 

FAIRBANKS, MORSE AND COMPANY. 

This company, through its Chicago office, constructed for 
the Commission and loaned to them without charge, a pair of 
special quick weighing beams for use on the car " Louisiana." 
This courtesy was especially appreciated as the company is 
neither directly nor indirectly interested in electric railway 
work. 

FELT AND TARRANT COMPANY. 

This company very materially aided the Executive Committee 
in the working up of the great mass of data by the loan of one 
of its well-known comptometers, which was used for several 
months without charge to the Commission. 



APPENDIX B 603 

GENERAL ELECTRIC COMPANY 

The General Electric Company through its representative 
on the Advisory Committee, Mr. A. H. Armstrong, made most 
valuable suggestions in regard to the work of the Commission. 
The local representative in charge of the exhibit at the St. Louis 
Exposition, Mr. F. H. Gale, was always ready to assist in the 
work in every way possible. The company loaned to the Com- 
mission one of its recording amimeters during the entire series 
of tests both at St. Louis and in Central Indiana. The Com- 
pany furnished without cost to the Commission, the necessary 
supplies for operating this instrument, which latter proved to 
be invaluable in the work of the Commission. 

ROBERT W. HUNT COMPANY. 

The Hunt Company furnished the industrial locomotive and 
its equipment, the tests on which are given in Chapter XL 
This company also furnished all electrical energy consumed in 
the tests on the locomotive, entirely free of charge to the Com- 
mission. The local representative of the company also assisted 
materially in these tests. 

THE INDIANA UNION TRACTION COMPANY. 

Early in the development of the work of the Commission, 
this company, through Mr. Geo. F. McCulloch, its president at 
the time, placed at the disposal of the Commission a stretch of 
track on the northern division of the system. As soon as the 
work at St. Louis was completed, the test corps was transferred 
to Anderson, Indiana, where the company furnished excellent 
office and drawing room facihties free to the Commission. 

Mr. A. L. Drum, general manager, Mr. A. S. Richey, elec- 
trical engineer, and Mr. C. A. Baldwin, superintendent of 
transporation, cooperated with the Executive Committee in 
arranging the details of the tests on the car '^ Louisiana,'^ as well 
as those on the interurban car. Mr, Drum also arranged through 



604 ELECTRIC RAILWAY TEST COMMISSION 

Mr. J. L. Matson, superintendent of motive power, to place at 
the disposal of the Executive Committee the shop and yard 
facihties of the company, without expense to the Commission, 
the company charging merely the actual cost of such material 
and labor as it was called upon to furnish. Mr. Matson also 
made many valuable suggestions in regard to the mechanical 
and electrical equipment. 

The company loaned a pair of Baldwin trucks, a Westing- 
house type L4 controller, and four Westinghouse No. 85 motors, 
all of which were greatly needed for regular service. It also 
loaned car-wiring cables, resistance grids, and many other parts 
of the equipment of the " Louisiana." The company furthermore 
suppHed all electrical energy consumed in making the tests on 
the interurban car and on the " Louisiana," and, through its 
transportation department, arranged schedules for the operation 
of these cars, which, while not interfering with the regular 
service, would provide all the conditions necessary for the 
successful carrjdng out of the desired tests. The present pres- 
ident, Mr. A. L. Brady, instructed the officers of the company 
to aid the Executive Committee in every possible way. 

INGERSOLL-SAEGENT DRILL COMPANY. 

This company which supplied the compressors for the stor- 
age air brake system of the St. Louis Transit Company, mani- 
fested great interest in the air-braking tests. The representa- 
tive of the company, Mr. L. I. Wightman, assisted materially 
in the air compression station tests described in Chapter VII. 

E. H. LINLEY SUPPLY COMPANY. 

Mr. E. H. Linley, president of the company, showed much 
interest in the tests on the effect of alternating current in steel 
rails. He supplied, without expense to the Commission, a num- 
ber of pieces of steel of various kinds, and of different lengths 
and cross-sections. The tests on these steel sections are given 
in Chapter XIII. 



APPENDIX B 605 

LOUISIANA PURCHASE EXPOSITION COMPANY. 

The President of the Exposition, Hon. David R. Francis, 
made the work possible by the official appointment of the mem- 
bers of the Electric Railway Test Commission. The Exposition 
Company, by placing at the disposal of the Commission the 
facihties afforded by the presence of apparatus arranged pri- 
marily for exhibit purposes, made possible the testing of this 
apparatus for the securing of scientific information. The Expo- 
sition Company constructed for test purposes two special test 
tracks located north of the Palace of Transportation, and sup- 
plied the electrical energy used in all the tests made on the 
Exposition grounds. 

Through the civil engineering department and the mechan- 
ical and electrical department of the Division of Works, the 
testing tracks were installed and equipped for the work, the 
power for operating the car being obtained from the lines of 
the Intramural Railway. Through the cooperation of the 
mechanical and electrical department, the cable used for the 
purpose of connecting the exhibit space of the Bullock Electric 
Manufacturing Company with the test tracks, was installed. 
This department also erected the poles and trolley wire and in- 
stalled the bonds on the test track, and loaned a 100-kilowatt 
General Electric transformer for use in the alternating current 
rail and track tests. Through its chief, Mr. Ellicott, and its 
superintendent of construction, Mr. Dixon, the mechanical 
and electrical department aided the Commission in many ways. 

The Test Corps was accorded the privileges of employes of 
the Exposition, being given unlimited free admission to the 
grounds and buildings by day or night. The Exposition Com- 
pany, through the chief of the department of electricity, Pro- 
fessor W. E. Goldsborough, afforded ample office facihties in 
the Palace of Electricity. Professor Goldsborough, in the 
capacity of Chairman of the Executive Committee, gave his 
time and energies freely to the work at all times and by his 
perseverance, determination, and patience, carried through what 



606 ELECTRIC RAILWAY TEST COMMISSION 

was apparently an almost impossible task. The Conmiission is 
also indebted to the several superintendents of the department 
of electricity, Messrs. Cloyd Marshall, P. F. Williams, Frank 
Welyand, and P. E. Fansler, for many courtesies extended to 
the Test Corps. 

The department of transportation, through its chief, Mr. 
Willard A. Smith, also placed its facilities at the disposal of the 
Commission. During the convention of the American Street 
Railway Association, Mr. Smith provided quarters in the con- 
vention hall so that the work of the Commission might be prop- 
erly recognized. 

THE MCGRAW PUBLISHING COMPANY. 

In addition to his personal subscription as a member of the 
Commission, Mr. James H. McGraw, in his capacity as presi- 
dent of the McGraw Publishing Company, undertook the entire 
financial responsibility of publishing the Report. Mr. Edward 
Caldwell, manager of the book department, was also greatly 
interested in the matter. He assisted the editors in many 
ways and arranged to have Mr. 0. A. Kenyon, of his department, 
aid in the work; this being peculiarly fitting, as he had served 
the Commission as a member of the Test Corps, and was, there- 
fore, personally interested. 

NATIONAL ELECTRIC COMPANY. 

The National Electric Company suppHed a motor-compressor 
equipment for use in connection with the tests upon the Hues 
of the St. Louis Transit Company, in order that a comparison 
might be made between the storage-air system and the motor- 
compressor system. It supplied a second equipment for instal- 
lation upon the " Louisiana," including a five horse power motor- 
compressor with reservoir, governor, valves, brake cylinder, and 
accessories. The chief engineer, Mr. C. P. Tolman, offered 
many valuable suggestions in regard to the air-brake tests, as 



APPENDIX B 607 

well as personal assistance when this was requested. The 
company was ready at all times to loan apparatus or in any 
other way to assist in the work of the Commission. 

NORTHERN ELECTRICAL MANUFACTURING COMPANY. 

This Company had a very complete motor-driven machine 
tool exhibit in the Palace of Electricity at the St. Louis Expo- 
sition. This exhibit was placed at the disposal of the Execu- 
tive Committee on several occasions during the progress of the 
work at St. Louis. 

OHIO STATE UNIVERSITY. 

Ohio State University, through Professor F. C. Caldwell, 
assisted in the work by loaning to the Commission apparatus 
for determining the speed of the cars, as well as a number of 
electrical instruments which were used in the tests at St. Louis. 

PRESSED STEEL CAR COMPANY. 

The Pressed Steel Car Company, through its president, Mr. 
J. W. Friend, and its representative at the St. Louis Exposition, 
Mr. C. M. Mendenhall, furnished to the Commission a steel flat 
car of 100,000 pounds capacity complete with trucks for use in 
connection with the air-resistance tests. The company also 
prepaid the freight on this car to Anderson, Indiana. The 
value of this contribution to the work is apparent from the 
description of the '^Louisiana," of which the flat car was an 
important part. 

PURDUE UNIVERSITY. 

Purdue University, through the head of the electrical engi- 
neering department, Prof. W. E. Goldsborough, and Assistant 
Professors H. T. Plumb and J. W. Esterline, contributed largely 
to the success of the tests, placing at the disposal of the Com- 
mission a considerable number of electrical instruments. At 
the close of the work, through its president. Dr. W. E. Stone, 



608 ELECTRIC RAILWAY TEST COMMISSION 

the broad cooperative policy of the University was shown in 
the agreement between the Commission, the American Street 
and Interurban Railway Association, and Purdue University, 
whereby the University agreed to cooperate with the Associa- 
tion in further tests by housing and caring for the "Louisiana" 
without cost to the Association. The University further per- 
mitted Professor Plumb and eight of its students to cooperate 
with the Executive Committee in making the tests on Car No. 
284, to which work Professor Plumb devoted much time and 
attention after returning to his University work. 

QUEEN AND COMPANY. 

This company loaned to the Commission for use in the air 
resistance tests, a pair of cup anemometers which were stationed 
at the ends of the test track on the Indianapolis and Logansport 
line of the Indiana Union Traction Company. This apparatus 
was employed in the determination of the velocity of the wind, 
which was a matter of considerable importance in the tests 
described in Chapter XVI. 

ST. LOUIS CAR COMPANY. 

In conjunction with the Westinghouse Traction Brake Com- 
pany and the Westinghouse Electric Manufacturing Company, 
the St. Louis Car Company placed at the disposal of the Com- 
mission a single-truck city car which was exhibited on the test 
tracks north of the Palace of Transportation at the World's 
Fair. Through the officers of the company, every courtesy was 
extended to the members of the Executive Committee. This 
car is the one considered in Chapters II, V, and X, and is 
fully described in Chapter I. 

STANDARD UNDERGROUND CABLE COMPANY. 

The Standard Underground Cable Company, through its 
Chicago manager, Mr. Wylie, offered to supply, free of cost to 



APPENDIX B 609 

the Commission, the cable for connecting the space of the Bul- 
lock Electric Manufactm'ing Company with the test tracks on 
the Exposition Grounds. This proposition would have been 
gladly accepted were it not for the fact that another company's 
courtesy in this connection had been previously accepted. The 
kindness in making this offer was duly appreciated by the mem- 
bers of the Coramission. 

THE TEST CORPS. 

While the Commission is under obligation to the various 
members of the Test Corps, as stated in the letter of transmittal 
at the beginning of the Report, it is felt that additional recog- 
nition should be given to Messrs. R. J. McNitt, Will Spalding, 
and C. C. Myers for the great interest which they showed in the 
work after they had severed their connection with the Test 
Corps, by aiding very materially in working up the final data 
contained in the Report. 

WASHINGTON UNIVERSITY. 

The authorities of Washington University, at St. Louis, 
accorded the Executive Committee most courteous treatment 
upon every possible occasion. The University dormitory was 
placed at the disposal of the Test Corps at a nominal charge for 
a period of several weeks. Professor Nipher and Langsdorf 
also assisted the Executive Committee upon several occasions. 

WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY. 

Through Mr. Clarence Renshaw, a member of the Advisory 
Committee, this company made many valuable suggestions in 
regard to the work of the Commission. Throughout the entire 
series of tests, the company showed itself ready to loan the Com- 
mission whatever materials and supplies were needed. In con- 



610 ELECTRIC RAILWAY TEST COMMISSION 

junction with the Westinghouse Traction Brake Company it 
placed at the disposal of the Executive Committee the single- 
truck city car exhibited on the test tracks north of the Palace 
of Transportation at the St. Louis Exposition. In con- 
junction with the Cincinnati Car Company, it submitted for 
test the double-truck interurban car, which was also exhibited 
at the Exposition. This car was equipped with the latest 
type electro-pneumatic control, and was of the latest design in 
all particulars. In connection with the special air resistance 
tests made in central Indiana, the company further manifested 
its cooperation by the loan of twenty extra heavy gird resis- 
tance frames for controlling the speed of the " Louisiana," 
an L4 controller, and two 600-ampere circuit-breakers. The 
manager of the Westinghouse exhibit at the Louisiana Purchase 
Exposition, Mr. W. K. Dunlap, was at all times ready to aid 
in the work of the Commission, and his cooperation was greatly 
appreciated. 

WESTINGHOUSE TRACTION BRAKE COMPANY. 

The Westinghouse Traction Brake Company, which has 
always been much interested in tests of railway apparatus, did 
everything in its power to promote the work of the Commission. 
By cooperation with the St. Louis Car Company, the St. Louis 
Transit Company, and Cincinnati Car Company, and the West- 
inghouse Electric Manufacturing Company, it placed at the dis- 
posal of the Commission several braking equipments for testing 
purposes. Among these were the magnetic brake placed on the 
St. Louis Car Company's interurban car, and the Storage Sys- 
tem of air-braking, such as is employed by the St. Louis Transit 
Company. The company also supplied a considerable amount 
of apparatus for use, including a special recording pressure 
gage. It furnished a competent operator for the tests on a 
single-truck city car, this operator working under the direction 
of the Executive Committee. The local representative in charge 
of the exhibit at the St. Louis Exposition, Mr. Townsend, was 



APPENDIX B 611 

indefatigable in his efforts to further the work of the Commis- 
sion. The chief mechanical engineer of the company, Mr. E. 
H. Dewson, contributed largely, both by suggestions and by 
personal assistance, to the success of the tests on the single- 
truck car. Mr. Ellicott, general manager of the company, also 
manifested a practical interest in the tests on this car. 

WESTON ELECTRICAL INSTRUMENT COMPANY. 

A large number of the instruments used, especially in the 
tests on Car No. 284 and on the '^Louisiana," were supplied by 
the Weston Electrical Instrument Company, which company 
offered to furnish as many instruments as might be required 
for all parts of the work. These were all new instruments 
supplied either from its large exhibit in the Palace of Electricity 
or directly from the factory. They were given to the Commis- 
sion on very short notice and without restriction. Further- 
more, the company refused to accept compensation for damage 
to instruments, which, while slight in any one case, amounted 
in the aggregate to a considerable sum, as a number of instru- 
ments were used. These instruments, of both direct and alter- 
nating current types, comprised ammeters, voltmeters, and 
wattmeters of various types and ranges. 

UNITED RAILWAYS OF ST. LOUIS. 

(Formerly the St. Louis Transit Company.) 

A short time before the opening of the Exposition, the St. 
Louis Transit Company installed upon its Unes the Westing- 
house Traction Brake Company's system of braking by means 
of storage air. The Transit Company placed at the disposal 
of the Commission, for the purpose of testing, such parts of 
this system as were deemed necessary. The company also 
placed at the disposal of the Commission one of its latest types 
of double-truck cars for a considerable period of time. The 
faciUties of the repair shops were also placed at the disposal of 



612 ELECTRIC RAILWAY TEST COMMISSION 

the Executive Committee in the work incident to rearranging 
and constructing apparatus for the car tests as well as for the 
compressor station tests. The company supplied the necessary- 
power for all of these tests, and furnished transportation to the 
Test Corps while it was engaged in this work. 

Special mention should also be made of the courtesies ex- 
tended by the general manager, Captain Robert McCulloch, by 
the assistant general manager, Mr. Richard McCulloch, and 
by the master mechanic, Mr. Michael O'Brien. 

UNITED STATES GOVERNMENT. 

The Department of Commerce and Labor, through the Na- 
tional Bureau of Standards, rendered invaluable service by 
placing at the disposal of the Commission its standardization 
laboratory installed in the Palace of Electricity at the Exposi- 
tion. Through the chief of the Bureau, Dr. S. W. Stratton, 
and his chief assistants, Prof. E. B. Rosa, Dr. Wolf, Dr. M. G. 
Lloyd, and other members of the staff, the exceptional facili- 
ties afforded by this laboratory were made available to the Com- 
mission. In the laboratory were installed many types of appa- 
ratus for making calibrations of electrical instruments, and the 
instruments used in the tests were frequently standardized 
without expense to the Commission. The various members of 
the corps of the National Bureau of Standards also contributed 
to the success of the work by suggestions and practical assis- 
tance. 

The Coast and Geodetic Survey Department loaned to the 
Commission, during the time of the St. Louis tests, a powerful 
and accurate chronograph which was used in connection with 
the speed measurements in the tests upon the single-truck 
city car. 

The Weather Bureau also furnished much information and 
data relating to temperature, moisture, and the velocity and 
direction of the wind, both at St. Louis and at Indianapolis. 



APPENDIX B 613 

UNIVERSITY OF ILLINOIS. 

Through Professor Morgan Brooks and Assistant Professor 
Williams, the University of Ilhnois assisted in the work by 
loaning to the Commission a number of electrical instruments 
which were used in the tests at St. Louis. 

UNIVERSITY OF WISCONSIN. 

Through the head of the electrical department, Prof. D. C. 
Jackson, the University of Wisconsin contributed to the work 
of the Commission by the loan of numerous instruments. The 
University authorities, through President C. R. Van Hise, Dean 
F. E. Turneaure, and Professor Jackson, also aided the Com- 
mission by granting a leave of absence to Prof. B. V. Swenson, 
assistant superintendent of tests, for the purpose of enabling 
him to take up the work of the Commission. Through Prof. 
J. W. Shuster, the University assisted in the work on the rail 
tests, by making magnetic measurements on samples of rail 
submitted to it. 



INDEX. 



¥ 



Acceleration, corrections for, 474. 
power consumption during, 200. 
tests, 197. 

with Westinghouse multiple unit 
control, 229. 
Acknowledgments, 593. 
Air brake, individual motor-com- 
pressor (see brake), 57, 296. 
straight (see brake), 150. 
Air pressure dynamometers, 488. 
resistance, car body, 565. 
car body data, 562-563. 
curves, flat vestibule, 554. 
parabolic vestibule, 553. 
parabolic wedge vestibule, 

553. 
standard vestibule, 555. 
up to 100 miles per hour, 565 
-568. 
for different speeds, 534. 
its effect upon train resistance, 

566. 
power absorbed by vestibules, 

569-572. 
front vestibule, 564. 
rear vestibule, 564. 
table up to 100 miles per hour, 

569. 
vestibule data, 558-561. 
tests, 534. 

arrangement of apparatus, 

529. 
description, 546. 
direction and velocity of wind, 

535. 
discussion, 563. 
profile of track, 490. 



Air resistance tests. — Continiied. 
results, 552. 

schedule of runs with para- 
bolic vestibule, 537, 542. 
schedule of runs with para- 
bolic wedge vestibule, 538. 
schedule of runs with flat ves- 
tibule, 543. 
schedule of runs with stand- 
ard vestibule, 545. 
speed measurement, 546. 
Alternating current losses in pipe 
sections, 424. 
in rails (see rail) . 
in rails and other steel and iron 

sections, 389. 
in round sections, 418, 420. 
in square sections, 416, 422. 
in track, 432. 

description of tests, 439. 
description of track, 433. 
American Gage Co., 598. 
American Street and Interurban 

Railway Association, 598. 
American Street Railway Associa- 
tion, cooperation with Com- 
mission, 5. 
American Steel and Wire Co., 598. 
Ammeter, General Electric record- 
ing, 71. 
Anchor tests, 381. 

Apparatus for making complete 
graphical record of car test, 157. 

Baldwin Locomotive Works, 599. 

trucks, construction of, 504, 
Ball bearings, 51 X, 

615 



616 



INDEX 



Brakes, Individual motor-compres- 
sor system, National Elec- 
tric Co., 57, 296. 
electrical connections for, 305. 
piping for, 302. 
storage air system, 47, 58, 296. 

braking equipment, 261. 
Westinghouse straight air system, 
150. 
with motor-compressor, 70. 
Westinghouse magnetic, 45 
braking current, 77. 
description of, 3, 39. 
diagram of connections, 343. 
heating of motors, 109. 
regulating devices, 342. 
tractive effort, 356. 
Braking, air, braking distances, 324. 
braking force, 324. 
braking period, 324. 
comparison of stand test, with 

service test, 322. 
discussion of results, 319. 
energy consumption, 324. 
energy consumption per cubic 

foot air, 294. 
leakage tests, 327. 
maximum deceleration, 324. 
motor-compressor vs. storage 

systems, 319. 
stand test, connections for re- 
sistance measurements, 316. 
stand tests of motor-compres- 
sor, 314. 
storage system, 255. 
stand test of motor-compressor, 
294. 
brake shoe pressure, 329. 
city car, air per stop, 293. 
curve, 359. 
force, 335. 

force, method of finding, 351. 
magnetic, current consumption, 
338. 
distance, 338 
force, 338, 



Braking, magnetic. — Continued. 
period, 338. 
storage air, city car, average pres- 
sure in high pressure reser- 
voir, 293. 
power consumption per stop, 
293 
tests, 253. 

city car, results, 311. 
magnetic brakes, 338. 
Brill, G. J., Co., 599. 
Buffers to take up vibration, 523. 
Bullock Electric Mfg. Co., 599. 
Bureau of standards, 29. 

Carbon resistance, 398. 
Car body used by United Railways 
of St. Louis, 47, 48. 
data, heavy city service, 583, 
588. 

heavy interurban, 586, 589. 

light city service, 582, 587. 

light interurban, 585, 588. 
double-truck city, 46. 

brakes, 57. 

braking tests of, 292. 

colli pared with single-truck city, 
143. 

controller and wiring of, 56. 

discussion of results of brak- 
ing tests, 319. 

discussion of results of ser- 
vice tests, 140. 

energy consumption, 116. 

general dimensions and data, 
47, 52. 

general results of service tests, 
132, 135, 137, 139. 

motors, 47. 

passengers carried, 116, 141. 

power consumption, 142. 

results of braking tests, 311. 

schedule speed, 116. 

service tests of, 116. 

stops per mile, 116, 141. 

temperature measurement, 142. 



I 



INDEX 



617 



Car, double-truck city. — Continued. 

time of stop, 116. 

trucks and running gear, 52 

weight of, 125. 

wiring diagram, 121. 
double-truck interurban, 58. 

body, 59. 

brakes, 70. 

controller and wiring, 70. 

equipment of, 65. 

general dimensions and data, 
59, 60. 

trucks and running gear, 66. 

weight of four-motor equip- 
ment complete, 69. 
equipment used by Indiana Union 

Traction Co., 149. 
interurban acceleration distance, 
228. 

acceleration period, 228, 

acceleration tests, 227. 

average speed, 192. 

braking tests, 324. 

comparison with city cars as to 
speed, power consumption, 
etc., 193. 

current consumption, 191. 

diagram of connections for ser- 
vice test, 162. 

discussion of results of accelera- 
tion tests, 241. 

discussion of results of braking 
tests, 334. 

discussion of results of tests, 189. 

energy consumption of, 189, 192. 
per stop, 327. 

graphical results of braking 
tests, 336. 

high speed, 573. 

line pressure, 145. 

passenger load, 151, 172. 

power consumption, 145. 

results of acceleration tests, 241. 

results braking tests, 324. 

results of service tests, 175, 178, 
181, 185, 187. 



Car, interurban. — Continued. 

results of service tests (graphi- 
cal), 173. 
service tests of, 145. 
speed, 146. 
stops per mile, 146. 
temperature rise in motors, 

146. 
total weight, 151. 
weight equipped, 325. 
resistance, average, 485. 
single-truck city, acceleration, 106. 
acceleration distance, 199. 
acceleration period, 199. 
acceleration tests of, 199 
body, 39. 

braking current, 77. 
braking tests of, 338. 
compared with double-truck 

city, 143. 
controllers and wiring of, 46. 
current consumption of, 77. 
deceleration, 107. 
discussion of results of acceler- 
ation tests, 222. 
discussion of results of brak- 
ing tests, 354, 366. 
discussion of results of ser- 
vice tests, 106. 
energy consumption, 108. 
gear ratio, 43. 
general dimensions and data, 

37. 
general results of service tests, 

92, 95, 99, 102. 
general results of service test 
(curves), 93, 96, 100, 104. 
graphical results of braking 

tests, 362. 
gross weight of, 41. 
k.w. per car mile, 77. 
k.w. per ton mile, 77. 
method of conducting service 

tests, 81. 
motors, 41. 
power consumption of, 77. 



618 



INDEX 



Car, single-truck city. — Continued. 
power consumption during ac- 
celeration, 200. 
power vs. hand brake, 107. 
results of acceleration tests, 

211. 
results of braking tests, 338. 
retardation, 107. 
service tests of, 76 
speed average, 77. 
speed ma:jfimum, 77. 
speed performance, 106. 
speed schedule, 77. 
. temperature data. 111. 
total weight, 79. 
truck and running gear, 41, 42. 
working up results of service 
tests, 85. 
trailer, 152. 

wiring diagram "Louisiana," 507. 
Chapman Double-Ball Bearing Co., 
600. 
construction of, 511. 
Christensen motor-compressor brak- 
ing apparatus, 57, 296. 
Cincinnati Car Co., 600= 
City car (see car), 338. 
City car data (see car). 

Energy and power consumption of 
double-truck city car, 116. 
of interurban car, 145, 189, 191, 

192. 
multiple unit control apparatus, 

237. 
single-truck city car, 77, 108. 
Committees, various, iv. 
Control, detailed description of West- 
inghouse multiple unit system, 
229. 
energy consumed by multiple unit 

control apparatus, 237. 
Westinghouse multiple unit, ad- 
justment of limit switch, 232. 
time lag in, 251. 

effect of adjustment of time 
limit switch, 250. 



Control, Westinghouse multiple unit. 
— Continued 
Westinghouse pneumatic system, 
59, 229. 
Controllers, diagram of wiring B 23 
Westinghouse, 344. 
G. E. Type K 28, 47, 56. 
master for Westinghouse multiple 

unit control, 231. 
power connections of Westinghouse 

B 23, 202. 
storage battery locomotive, 372. 
Westinghouse B 23, 344. 
Westinghouse multiple unit, 59, 
149. 
Cooperators, 597. 
Cornell University, 601. 
Counter E.M.F. in rails, 390. 
Crosby Steam Gage Co., 601. 
Current density effect on rail drop, 
407. 

Dayton Electrical Manufacturing 

Company, 601. 
Deceleration average in braking tests 
of city car, 358. 
methods of finding, 328, 350, 
Distance recorder, 206. 
Double-truck car (see car). 
Dynamometer car, description of, 491. 
safety locking device, construction 

of, 508, 509. 
sketch of, a, 517. 
Dynamometers, calibration of, 530. 
for measurement of air pressure, 
488, 518. 
Dynamometer, oil, 376. 

Electric Railway and Equipment 
Co., 602. 

Electric Railway Test Commission, 
Organization, 1. 

Electric Storage Battery Co., 602. 

Engineering committee, on test of 
city and surburban equip- 
ments, 8. 



INDEX 



619 



Engineering committee. — Continued. 

on test of heavy traction equip- 
ments, 9. 

on test of interurban equip- 
ments, 9. 

on new electric railway systems, 
9. 

Fairbanks, Morse & Co., 602. 
Feeder S3'stems of Indiana Union 

Traction Co., 147. 
of United Railways of St. Louis, 

119. 
Felt and Tarrant Co., 602. 
Financial assistance, 593. 
Flat car, pressed steel, construction 

of, 502. 
Frequency effect on rail drop, 406. 

General Electric Co., 603. 
Grades, allowance for in testing, 
474. 

High speed car (proposed), 573. 
Horizontal effect of industrial loco- 
motive, 384. 
measurement of, 376, 474. 
Hunt, Robert W., Co., 603. 

Indiana Union Traction Co., 603. 
Indiana Union Traction Company's 

system, 148. 
Industrial storage battery locomo- 
tive, test of, 369. 
controller, 372. 
discussion of results of tests, 

379. 
horizontal effort, 369, 384. 
performance, 370. 
Ingersoll-Sargent Drill Co., 604. 
Impedance double track, 446. 
and trolley, 446. 
single track, 447. 

and trolley, 447. 
tracks, discussion, 451. 



Instruments, chronograph, 83. 
connections of for service tests, 86, 

126. 
measuring horizontal effort, 376. 
measurement of speed (see speed), 

82. 
for recording distance, 206. 
General Electric recording amme- 
ter, 71. 
recording, 71, 157. 
connections for, 85. 
Interurban car (see car), 
data (see car), 
for high speed, 573. 

Linley, E. H. Supply Co., 604. 
Ijocomotive (see Industrial). 
" Louisiana," Description of the, 488. 
Louisiana Purchase Exposition Co., 
605. 

Magnetic brake (see brake), 39. 
McGraw Publishing Co., 606. 
Memorandum for Electric Railway 

Test Commission, 2. 
Motors, connections for test of 
compound wound stationary 
~ motor, 269. 
division of current and E.M.F. 
between two motors in series 
and parallel, 94, 97, 101, 105. 
G.E. No. 54, 47, 54, 56. 

No. 54, performance curves, 120. 
heating of, due to magnetic brake, 

109. 
output rating by A.I.E.E., 54. 
shop test of railway, 80. 
temperature measurements, 109. 
Westinghouse No. 56, 41, 43, 80. 
No. 85, 59, 67. 

performance curves, 150. 
Multiple imit control acceleration 
tests, 229. 

National Electric Co., 606. 
Northern Electrical Mfg. Co., 607. 



620 



INDEX 



Ohio State University, 607. 
Oil dynamometer, 376. 

Parabolic vestibule construction of, 

499. 
Pipe sections a.c. losses in, 424. 
Plans of commission, Outline of, 7. 
Power consumption during accelera- 
tion, 200. 
measurement by three volt-meter 

method, 399. 
taken at different speeds by differ- 
ent head vestibules, 556. 
by different rear vestibules, 
557. 
Pressed Steel Car Co., 607. 
Purdue University, 607. 

Queen & Co., 608. 

Rails, alternating current losses in, 
389. 
counter E.M.F. in, 390. 
drop in, 426, 428. 
impedance-resistance ratios, 426 

429. 
power-factors, 427, 429. 
used by United Railways of St. 

Louis, 119. 
tests of, 56 pounds per yard, 393. 
80 pounds per yard, 393, 
carbon resistance, 398. 
diagram of electrical connec- 
tions, 395, 396, 397, 398. 
discussion of, 426. 
gas pipe, 394. 
graphical data, 404, 412. 
power measurements, 399. 
results of, 401. 
round sections, 394. 
square sections, 394, 
temperature measurements, 400. 
Report, General description of, 31. 

of various committees, 10. 
Resistance carbon, 398. 
measurements, connections for, 316. 



Resistance. — Continued, 

of rails, 45. 

of double-track, 450. 

of single-track, 450. 
Retardation (see Deceleration), 328. 

St. Louis Car Co., 608. 

Sand box, capacity of, for interurban 

service, 65. 
Scales, quick weighing, 519. 
Service tests, 33. 

definition of, 36. 
Single-truck car (see car), 338. 
Skin effect, 390. 

Speed measurement, Apple genera- 
tor, 82, 163. 
Apple generator, 349. 
Boyer recorder, 82, 84, 130. 
chronograph, 83. 
contact device, 206. 
magneto generator, 130. 
tests of single-truck city car, 
43. 
Stand test of air compressor com- 
pared with actual performance 
on car, 322. 
Standard Undergromid Cable Co., 

608. 
Stops, duration of, 116. 

per mile city service, 116, 141. 
interurban service, 146. 
Storage air system, air lost by leak- 
age, 256. 
automatic controller, 285. 
braking equipment, 261. 
capacity of station, 295. 
compared with motor-compres- 
sor systems, 319. 
compressor efficiency, 269. 
compressor-station tests, 255. 
connections for calibrating car 

gages, 268o 
discussion of results of compres- 
sor station test, 284. 
electrical connections for test^ 
264. 



INDEX 



621 



Storage air system. — Continued. 

heat absorbed by cooling water, 

256. 
connections for charging cars, 

259. 
interval of compressor runs, 256. 
loss in air lift, 268. 
measurement of volume of air 

compressed, 262. 
motor-compressor, 2o8. 
plan of station, 257. 
power consumption, 256. 
reservoir pressure, 256. 
results of station tests, 277. 
summary of compressor station 

tests, 289. 
tank capacity, 260. 
battery locomotive, Test of, 369. 

Test car, Louisiana, 488. 
corps, 24, 609. 
general description of, 29. 
Three voltmeter method, 399. 
Tool box for interurban cars, 65. 
Track, alternating and continuous 
current losses in, 390. 
gage used by United Railways of 

St. Louis, 117. 
impedance tests, connections, 440. 
discussion of results, 450. 
results of tests, 443. 
power factor for different frequen- 
cies and currents, 444-449. 
power loss for different frequencies 

and currents, 444-449. 
pressure drop for different frequen- 
cies and currents, 444—449. 
rails used by United Railways of 

St. Louis, 119. 
tests, power supply, 435. 
Tracks used by Commission at Ex- 
position, 2. 
Trailer, 152. 



Train resistance, air component, 
485. 
as affected by air resistance, 566. 
effect of form of vestibule, 485. 
formulas, 465. 
tests, 463. 

discussion of, 485. 
for different speeds, 464. 
Treasurer's report, 594. 
Trucks, Baldwin, Construction of, 
504. 
heavy interurban, 66. 
general dimensions of single truck, 

41, 42. 
used by United Railways of St. 
Louis, 52. 

United Railways, 611. 

of St. Louis Park Ave. line (map), 
118. 
United States Government, 612. 
University of Illinois, 613. 
University of Wisconsin, 613. 

Vestibule, parabolic, construction of, 
499. 
standard. Construction of, 515, 516. 

Washington University, 609. 
Westinghouse Electric and Mfg. Co., 

609. 
Westinghouse Traction Brake Co., 

610. 
Weston Electrical Instrument Co., 

611. 
Wind direction and velocity, air re- 
sistance tests, 535; 
Wiring, double-truck city car, 56. 
interurban car, 70. 
dynamometer car, "Louisiana," 

507. 
single-truck city car, 46. 



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Deacidified using the Bookkeeper process. 
Neutralizing agent: Magnesium Oxide 
Treatment Date: April 2004 

PreservatlonTechnologies 

A WORLD LEADER IN PAPER PRESERVATION 

1 1 1 Thomson'Park Drive 
Cranberry Township, PA 16066 
(724)779-2111 



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